 Open in App
Not now

# Suffix Array | Set 1 (Introduction)

• Difficulty Level : Medium
• Last Updated : 15 Mar, 2023

We strongly recommend to read following post on suffix trees as a pre-requisite for this post.
Pattern Searching | Set 8 (Suffix Tree Introduction)
A suffix array is a sorted array of all suffixes of a given string. The definition is similar to Suffix Tree which is compressed trie of all suffixes of the given text. Any suffix tree based algorithm can be replaced with an algorithm that uses a suffix array enhanced with additional information and solves the same problem in the same time complexity (Source Wiki).
A suffix array can be constructed from Suffix tree by doing a DFS traversal of the suffix tree. In fact Suffix array and suffix tree both can be constructed from each other in linear time.
Advantages of suffix arrays over suffix trees include improved space requirements, simpler linear time construction algorithms (e.g., compared to Ukkonen’s algorithm) and improved cache locality (Source: Wiki)
Example:

```Let the given string be "banana".

0 banana                          5 a
1 anana     Sort the Suffixes     3 ana
2 nana      ---------------->     1 anana
3 ana        alphabetically       0 banana
4 na                              4 na
5 a                               2 nana

So the suffix array for "banana" is {5, 3, 1, 0, 4, 2}```

Naive method to build Suffix Array
A simple method to construct suffix array is to make an array of all suffixes and then sort the array. Following is implementation of simple method.

## CPP

 `// Naive algorithm for building suffix array of a given text` `#include ` `#include ` `#include ` `using` `namespace` `std;`   `// Structure to store information of a suffix` `struct` `suffix` `{` `    ``int` `index;` `    ``char` `*suff;` `};`   `// A comparison function used by sort() to compare two suffixes` `int` `cmp(``struct` `suffix a, ``struct` `suffix b)` `{` `    ``return` `strcmp``(a.suff, b.suff) < 0? 1 : 0;` `}`   `// This is the main function that takes a string 'txt' of size n as an` `// argument, builds and return the suffix array for the given string` `int` `*buildSuffixArray(``char` `*txt, ``int` `n)` `{` `    ``// A structure to store suffixes and their indexes` `    ``struct` `suffix suffixes[n];`   `    ``// Store suffixes and their indexes in an array of structures.` `    ``// The structure is needed to sort the suffixes alphabetically` `    ``// and maintain their old indexes while sorting` `    ``for` `(``int` `i = 0; i < n; i++)` `    ``{` `        ``suffixes[i].index = i;` `        ``suffixes[i].suff = (txt+i);` `    ``}`   `    ``// Sort the suffixes using the comparison function` `    ``// defined above.` `    ``sort(suffixes, suffixes+n, cmp);`   `    ``// Store indexes of all sorted suffixes in the suffix array` `    ``int` `*suffixArr = ``new` `int``[n];` `    ``for` `(``int` `i = 0; i < n; i++)` `        ``suffixArr[i] = suffixes[i].index;`   `    ``// Return the suffix array` `    ``return`  `suffixArr;` `}`   `// A utility function to print an array of given size` `void` `printArr(``int` `arr[], ``int` `n)` `{` `    ``for``(``int` `i = 0; i < n; i++)` `        ``cout << arr[i] << ``" "``;` `    ``cout << endl;` `}`   `// Driver program to test above functions` `int` `main()` `{` `    ``char` `txt[] = ``"banana"``;` `    ``int` `n = ``strlen``(txt);` `    ``int` `*suffixArr = buildSuffixArray(txt,  n);` `    ``cout << ``"Following is suffix array for "` `<< txt << endl;` `    ``printArr(suffixArr, n);` `    ``return` `0;` `}`

## Java

 `//importing the required packages` `import` `java.util.ArrayList;` `import` `java.util.Arrays;`   `class` `suffix_array {` `    ``public` `static` `void` `main(String[] args) ``throws` `Exception` `    ``{` `        ``String word = ``"banana"``;` `        ``String arr1[] = ``new` `String[word.length()];` `        ``String arr2[] = ``new` `String[word.length()];` `        ``ArrayList suffix_index` `            ``= ``new` `ArrayList();` `        ``int` `suffix_array[] = ``new` `int``[word.length()];` `        ``for` `(``int` `i = ``0``; i < word.length(); i++) {` `            ``arr1[i] = word.substring(i);` `        ``}` `        ``arr2 = arr1.clone();` `        ``Arrays.sort(arr1);` `        ``for` `(String i : arr1) {` `            ``String piece = i;` `            ``int` `index` `                ``= ``new` `suffix_array().index(arr2, piece);` `            ``suffix_index.add(index);` `        ``}` `        ``for` `(``int` `i = ``0``; i < suffix_array.length; i++) {` `            ``suffix_array[i] = suffix_index.get(i);` `        ``}` `        ``System.out.println(` `            ``"following is the suffix array for banana"``);` `        ``for` `(``int` `i : suffix_array) {` `            ``System.out.print(i + ``" "``);` `        ``}` `    ``}` `    `  `      ``//simple function to return the index of item from array arr[]` `    ``int` `index(String arr[], String item)` `    ``{` `        ``for` `(``int` `i = ``0``; i < arr.length; i++) {` `            ``if` `(item == arr[i])` `                ``return` `i;` `        ``}` `        ``return` `-``1``;` `    ``}` `}`

## Python3

 `# Naive algorithm for building suffix array of a given text` `import` `sys`     `class` `Suffix:` `    ``def` `__init__(``self``, index, suff):` `        ``self``.index ``=` `index` `        ``self``.suff ``=` `suff`   `# A comparison function used by sort() to compare two suffixes` `def` `cmp``(a, b):` `    ``return` `(a.suff < b.suff) ``-` `(a.suff > b.suff)`   `# This is the main function that takes a string 'txt' of size n as an` `# argument, builds and return the suffix array for the given string` `def` `build_suffix_array(txt, n):` `    ``# A structure to store suffixes and their indexes` `    ``suffixes ``=` `[Suffix(i, txt[i:]) ``for` `i ``in` `range``(n)]`   `    ``# Sort the suffixes using the comparison function` `    ``# defined above.` `    ``suffixes.sort(key``=``cmp``)`   `    ``# Store indexes of all sorted suffixes in the suffix array` `    ``suffix_arr ``=` `[suffixes[i].index ``for` `i ``in` `range``(n)]`   `    ``# Return the suffix array` `    ``return` `suffix_arr`   `# A utility function to print an array of given size` `def` `print_arr(arr):` `    ``for` `i ``in` `range``(``len``(arr)):` `        ``print``(arr[i], end``=``" "``)` `    ``print``()`   `# Driver program to test above functions` `def` `main():` `    ``txt ``=` `"banana"` `    ``n ``=` `len``(txt)` `    ``suffix_arr ``=` `build_suffix_array(txt, n)` `    ``print``(``"Following is suffix array for"``, txt)` `    ``print_arr(suffix_arr)`   `if` `__name__ ``=``=` `"__main__"``:` `    ``main()`

## C#

 `// Naive algorithm for building suffix array of a given text` `using` `System;` `using` `System.Linq;`   `class` `SuffixArray` `{` `    ``private` `readonly` `string` `_text;` `    ``private` `readonly` `int``[] _suffixArray;`   `    ``private` `struct` `Suffix` `    ``{` `        ``public` `int` `Index { ``get``; ``set``; }` `        ``public` `string` `Suff { ``get``; ``set``; }` `    ``}`   `    ``private` `static` `int` `CompareSuffixes(Suffix a, Suffix b)` `    ``{` `        ``return` `string``.Compare(a.Suff, b.Suff, StringComparison.Ordinal);` `    ``}`   `    ``public` `SuffixArray(``string` `text)` `    ``{` `        ``_text = text;`   `        ``var` `n = _text.Length;` `        ``var` `suffixes = ``new` `Suffix[n];`   `        ``for` `(``var` `i = 0; i < n; i++)` `        ``{` `            ``suffixes[i] = ``new` `Suffix` `            ``{` `                ``Index = i,` `                ``Suff = _text.Substring(i)` `            ``};` `        ``}`   `        ``Array.Sort(suffixes, CompareSuffixes);`   `        ``_suffixArray = ``new` `int``[n];` `        ``for` `(``var` `i = 0; i < n; i++)` `        ``{` `            ``_suffixArray[i] = suffixes[i].Index;` `        ``}` `    ``}`   `    ``public` `int``[] GetSuffixArray()` `    ``{` `        ``return` `_suffixArray;` `    ``}` `}`   `class` `Program` `{` `    ``static` `void` `Main(``string``[] args)` `    ``{` `        ``var` `txt = ``"banana"``;` `        ``var` `suffixArray = ``new` `SuffixArray(txt);` `        ``Console.WriteLine(``"Following is suffix array for "` `+ txt);` `        ``Console.WriteLine(``string``.Join(``" "``, suffixArray.GetSuffixArray().Select(x => x.ToString())));` `    ``}` `}`   `// This code is contributed by snehalsalokhe `

## Javascript

 `// Naive algorithm for building suffix array of a given text` `      ``// A comparison function used by sort() to compare two suffixes` `      ``function` `comp(a, b) {` `        ``const name1 = a.suff;` `        ``const name2 = b.suff;`   `        ``let comparison = 0;`   `        ``if` `(name1 > name2) {` `          ``comparison = 1;` `        ``} ``else` `if` `(name1 < name2) {` `          ``comparison = -1;` `        ``}` `        ``return` `comparison;` `      ``}`   `      ``// This is the main function that takes a string 'txt' of size n as an` `      ``// argument, builds and return the suffix array for the given string` `      ``function` `buildSuffixArray(txt, n) {` `        ``// A Array to store suffixes and their indexes` `        ``var` `suffixes = [];` `        ``// Store suffixes and their indexes in an array of objects.` `        ``// The object is needed to sort the suffixes alphabetically` `        ``// and maintain their old indexes while sorting`   `        ``for` `(``var` `i = 0; i < n; i++) {` `          ``var` `suffix = {};` `          ``suffix.index = i;` `          ``suffix.suff = txt.substr(i);` `          ``suffixes.push(suffix);` `        ``}`   `        ``// Sort the suffixes using the comparison function defined above.`   `        ``suffixes.sort(comp);`   `        ``// Store indexes of all sorted suffixes in the suffix array` `        ``var` `suffixArr = [];`   `        ``for` `(``var` `i = 0; i < n; i++) suffixArr[i] = suffixes[i].index;`   `        ``// Return the suffix array` `        ``return` `suffixArr;` `      ``}`   `      ``// A utility function to print an array of given size` `      ``function` `printArr(arr, n) {` `        ``for` `(``var` `i = 0; i < n; i++) {` `          ``console.log(arr[i]);` `        ``}` `      ``}`   `      ``// Driver program to test above functions`   `      ``var` `txt = ``"banana"``;` `      ``var` `n = txt.length;` `      ``var` `suffixArr = buildSuffixArray(txt, n);` `      ``console.log(``"Following is suffix array for "` `+ txt);` `      ``printArr(suffixArr, n);`

Output

```Following is suffix array for banana
5 3 1 0 4 2 ```

Time Complexity: O(n*k*Logn). if we consider a O(nLogn)) algorithm used for sorting. The sorting step itself takes O(n*k*Logn) time as every comparison is a comparison of two strings and the comparison takes O(K) time where K is max length of string in given array.
Auxiliary Space: O(n)

There are many efficient algorithms to build suffix array. We will soon be covering them as separate posts.
Search a pattern using the built Suffix Array
To search a pattern in a text, we preprocess the text and build a suffix array of the text. Since we have a sorted array of all suffixes, Binary Search can be used to search. Following is the search function. Note that the function doesn’t report all occurrences of pattern, it only report one of them.

## CPP

 `// This code only contains search() and main. To make it a complete running` `// above code or see https://ide.geeksforgeeks.org/oY7OkD`   `// A suffix array based search function to search a given pattern` `// 'pat' in given text 'txt' using suffix array suffArr[]` `void` `search(``char` `*pat, ``char` `*txt, ``int` `*suffArr, ``int` `n)` `{` `    ``int` `m = ``strlen``(pat);  ``// get length of pattern, needed for strncmp()`   `    ``// Do simple binary search for the pat in txt using the` `    ``// built suffix array` `    ``int` `l = 0, r = n-1;  ``// Initialize left and right indexes` `    ``while` `(l <= r)` `    ``{` `        ``// See if 'pat' is prefix of middle suffix in suffix array` `        ``int` `mid = l + (r - l)/2;` `        ``int` `res = ``strncmp``(pat, txt+suffArr[mid], m);`   `        ``// If match found at the middle, print it and return` `        ``if` `(res == 0)` `        ``{` `            ``cout << ``"Pattern found at index "` `<< suffArr[mid];` `            ``return``;` `        ``}`   `        ``// Move to left half if pattern is alphabetically less than` `        ``// the mid suffix` `        ``if` `(res < 0) r = mid - 1;`   `        ``// Otherwise move to right half` `        ``else` `l = mid + 1;` `    ``}`   `    ``// We reach here if return statement in loop is not executed` `    ``cout << ``"Pattern not found"``;` `}`   `// Driver program to test above function` `int` `main()` `{` `    ``char` `txt[] = ``"banana"``;  ``// text` `    ``char` `pat[] = ``"nan"``;   ``// pattern to be searched in text`   `    ``// Build suffix array` `    ``int` `n = ``strlen``(txt);` `    ``int` `*suffArr = buildSuffixArray(txt, n);`   `    ``// search pat in txt using the built suffix array` `    ``search(pat, txt, suffArr, n);`   `    ``return` `0;` `}`

## Python3

 `import` `sys`   `# A suffix array based search function to search a given pattern` `# 'pat' in given text 'txt' using suffix array suffArr[]` `def` `search(pat, txt, suffArr, n):` `  `  `    ``# Get the length of the pattern` `    ``m ``=` `len``(pat)` `    `  `    ``# Initialize left and right indexes` `    ``l ``=` `0` `    ``r ``=` `n``-``1` `    `  `    ``# Do simple binary search for the pat in txt using the built suffix array` `    ``while` `l <``=` `r:` `      `  `        ``# Find the middle index of the current subarray` `        ``mid ``=` `l ``+` `(r ``-` `l)``/``/``2` `        `  `        ``# Get the substring of txt starting from suffArr[mid] and of length m` `        ``res ``=` `txt[suffArr[mid]:suffArr[mid]``+``m]` `        `  `        ``# If the substring is equal to the pattern` `        ``if` `res ``=``=` `pat:` `          `  `            ``# Print the index and return` `            ``print``(``"Pattern found at index"``, suffArr[mid])` `            ``return` `          `  `        ``# If the substring is less than the pattern` `        ``if` `res < pat:` `          `  `            ``# Move to the right half of the subarray` `            ``l ``=` `mid ``+` `1` `        ``else``:` `          `  `            ``# Move to the left half of the subarray` `            ``r ``=` `mid ``-` `1` `            `  `    ``# If the pattern is not found` `    ``print``(``"Pattern not found"``)` `    `  `def` `buildSuffixArray(txt, n):` `  `  `    ``# Create a list of all suffixes` `    ``suffixes ``=` `[txt[i:] ``for` `i ``in` `range``(n)]` `    `  `    ``# Sort the suffixes` `    ``suffixes.sort()` `    `  `    ``# Create the suffix array` `    ``suffArr ``=` `[txt.index(suffix) ``for` `suffix ``in` `suffixes]` `    ``return` `suffArr`   `# Driver program to test above function` `def` `main():` `    ``txt ``=` `"banana"`  `# text` `    ``pat ``=` `"nan"`   `# pattern to be searched in text`   `    ``# Build suffix array` `    ``n ``=` `len``(txt)` `    ``suffArr ``=` `buildSuffixArray(txt, n)`   `    ``# search pat in txt using the built suffix array` `    ``search(pat, txt, suffArr, n)` `    ``return` `0`   `if` `__name__ ``=``=` `'__main__'``:` `    ``sys.exit(main())`   `# This code is contributed by Vikram_Shirsat`

## Javascript

 `// A suffix array based search function to search a given pattern` `      ``// 'pat' in given text 'txt' using suffix array suffArr[]` `      ``function` `search(pat, txt, suffArr, n) {` `        ``var` `m = pat.length; ``// get length of pattern`   `        ``// Do simple binary search for the pat in txt using the` `        ``// built suffix array` `        ``var` `l = 0;` `        ``var` `r = n - 1; ``// Initialize left and right indexes` `        ``while` `(l <= r) {` `          ``// See if 'pat' is prefix of middle suffix in suffix array` `          ``var` `mid = l + Math.floor((r - l) / 2);` `          ``var` `c = txt.substring(suffArr[mid]);` `          ``var` `res = 0;`   `          ``for` `(``var` `i = 0; i < m; i++) {` `            ``if` `(pat[i] == c[i]) {` `              ``continue``;` `            ``} ``else` `if` `(pat[i] < c[i]) {` `              ``res = -1;` `              ``break``;` `            ``} ``else` `{` `              ``res = 1;` `              ``break``;` `            ``}` `          ``}`   `          ``// If match found at the middle, print it and return` `          ``if` `(res == 0) {` `            ``console.log(``"Pattern found at index "` `+ suffArr[mid]);` `            ``return``;` `          ``}`   `          ``// Move to left half if pattern is alphabetically less than` `          ``// the mid suffix` `          ``if` `(res < 0) r = mid - 1;` `          ``// Otherwise move to right half` `          ``else` `l = mid + 1;` `        ``}`   `        ``// We reach here if return statement in loop is not executed` `        ``console.log(``"Pattern not found"``);` `      ``}` `      `  `      ``function` `comp(a, b) {` `        ``const name1 = a.suff;` `        ``const name2 = b.suff;`   `        ``let comparison = 0;`   `        ``if` `(name1 > name2) {` `          ``comparison = 1;` `        ``} ``else` `if` `(name1 < name2) {` `          ``comparison = -1;` `        ``}` `        ``return` `comparison;` `      ``}`   `      ``function` `buildSuffixArray(txt, n) {` `        ``// A Array to store suffixes and their indexes` `        ``var` `suffixes = [];` `        ``// Store suffixes and their indexes in an array of objects.` `        ``// The object is needed to sort the suffixes alphabetically` `        ``// and maintain their old indexes while sorting`   `        ``for` `(``var` `i = 0; i < n; i++) {` `          ``var` `suffix = {};` `          ``suffix.index = i;` `          ``suffix.suff = txt.substr(i);` `          ``suffixes.push(suffix);` `        ``}`   `        ``// Sort the suffixes using the comparison function defined above.`   `        ``suffixes.sort(comp);`   `        ``// Store indexes of all sorted suffixes in the suffix array` `        ``var` `suffixArr = [];`   `        ``for` `(``var` `i = 0; i < n; i++) suffixArr[i] = suffixes[i].index;`   `        ``// Return the suffix array` `        ``return` `suffixArr;` `      ``}` `      `  `      ``var` `txt = ``"banana"``; ``// text` `      ``var` `pat = ``"nan"``; ``// pattern to be searched in text`   `      ``// Build suffix array` `      ``var` `n = txt.length;` `      ``var` `suffArr = buildSuffixArray(txt, n);`   `      ``// search pat in txt using the built suffix array` `      ``search(pat, txt, suffArr, n);`

## Java

 `import` `java.io.*;`   `public` `class` `GFG {` `  ``// A suffix array based search function to search a given pattern` `// 'pat' in given text 'txt' using suffix array suffArr[]` `static` `void` `search(String pat, String txt, ``int``[] suffArr, ``int` `n)` `{`   `    ``// Get the length of the pattern` `    ``int` `m = pat.length();`   `    ``// Initialize left and right indexes` `    ``int` `l = ``0``;` `    ``int` `r = n - ``1``;`   `    ``// Do simple binary search for the pat in txt using the built suffix array` `    ``while` `(l <= r) {`   `        ``// Find the middle index of the current subarray` `        ``int` `mid = l + (r - l) / ``2``;`   `        ``// Get the substring of txt starting from suffArr[mid] and of length m` `        ``String res = txt.substring(suffArr[mid], suffArr[mid] + m);`   `        ``// If the substring is equal to the pattern` `        ``if` `(res.equals(pat)) {`   `            ``// Print the index and return` `            ``System.out.println(``"Pattern found at index "` `+ suffArr[mid]);` `            ``return``;` `        ``}`   `        ``// If the substring is less than the pattern` `        ``if` `(res.compareTo(pat) < ``0``) {`   `            ``// Move to the right half of the subarray` `            ``l = mid + ``1``;` `        ``} ``else` `{`   `            ``// Move to the left half of the subarray` `            ``r = mid - ``1``;` `        ``}` `    ``}`   `    ``// If the pattern is not found` `    ``System.out.println(``"Pattern not found"``);` `}`   `static` `int``[] buildSuffixArray(String txt, ``int` `n)` `{`   `    ``// Create a list of all suffixes` `    ``String[] suffixes = ``new` `String[n];` `    ``for` `(``int` `i = ``0``; i < n; i++) {` `        ``suffixes[i] = txt.substring(i, n);` `    ``}`   `    ``// Sort the suffixes` `    ``java.util.Arrays.sort(suffixes);`   `    ``// Create the suffix array` `    ``int``[] suffArr = ``new` `int``[n];` `    ``for` `(``int` `i = ``0``; i < n; i++) {` `        ``suffArr[i] = txt.indexOf(suffixes[i]);` `    ``}` `    ``return` `suffArr;` `}`   `// Driver program to test above function` `public` `static` `void` `main(String[] args)` `{` `    ``String txt = ``"banana"``; ``// text` `    ``String pat = ``"nan"``; ``// pattern to be searched in text`   `    ``// Build suffix array` `    ``int` `n = txt.length();` `    ``int``[] suffArr = buildSuffixArray(txt, n);`   `    ``// search pat in txt using the built suffix array` `    ``search(pat, txt, suffArr, n);` `}` `}`   `//This code is contributed by shivamsharma215`

## C#

 `using` `System;`   `class` `GFG {` `    ``// A suffix array based search function to search a` `    ``// given pattern 'pat' in given text 'txt' using suffix` `    ``// array suffArr[]` `    ``static` `void` `Search(``string` `pat, ``string` `txt,` `                       ``int``[] suffArr, ``int` `n)` `    ``{` `        ``// Get the length of the pattern` `        ``int` `m = pat.Length;`   `        ``// Initialize left and right indexes` `        ``int` `l = 0;` `        ``int` `r = n - 1;`   `        ``// Do simple binary search for the pat in txt using` `        ``// the built suffix array` `        ``while` `(l <= r) {` `            ``// Find the middle index of the current subarray` `            ``int` `mid = l + (r - l) / 2;`   `            ``// Get the substring of txt starting from` `            ``// suffArr[mid] and of length m` `            ``string` `res = txt.Substring(suffArr[mid], m);`   `            ``// If the substring is equal to the pattern` `            ``if` `(res.Equals(pat)) {` `                ``// Print the index and return` `                ``Console.WriteLine(``"Pattern found at index "` `                                  ``+ suffArr[mid]);` `                ``return``;` `            ``}`   `            ``// If the substring is less than the pattern` `            ``if` `(res.CompareTo(pat) < 0) {` `                ``// Move to the right half of the subarray` `                ``l = mid + 1;` `            ``}` `            ``else` `{` `                ``// Move to the left half of the subarray` `                ``r = mid - 1;` `            ``}` `        ``}`   `        ``// If the pattern is not found` `        ``Console.WriteLine(``"Pattern not found"``);` `    ``}`   `    ``static` `int``[] BuildSuffixArray(``string` `txt, ``int` `n)` `    ``{` `        ``// Create a list of all suffixes` `        ``string``[] suffixes = ``new` `string``[n];` `        ``for` `(``int` `i = 0; i < n; i++) {` `            ``suffixes[i] = txt.Substring(i, n - i);` `        ``}`   `        ``// Sort the suffixes` `        ``Array.Sort(suffixes);`   `        ``// Create the suffix array` `        ``int``[] suffArr = ``new` `int``[n];` `        ``for` `(``int` `i = 0; i < n; i++) {` `            ``suffArr[i] = txt.IndexOf(suffixes[i]);` `        ``}` `        ``return` `suffArr;` `    ``}`   `    ``// Driver program to test above function` `    ``static` `void` `Main(``string``[] args)` `    ``{` `        ``string` `txt = ``"banana"``; ``// text` `        ``string` `pat` `            ``= ``"nan"``; ``// pattern to be searched in text`   `        ``// Build suffix array` `        ``int` `n = txt.Length;` `        ``int``[] suffArr = BuildSuffixArray(txt, n);`   `        ``// search pat in txt using the built suffix array` `        ``Search(pat, txt, suffArr, n);` `    ``}` `}` `// This code is contributed by prajwal kandekar`

Output:

`Pattern found at index 2`

Time Complexity: O(mlogn)
Auxiliary Space: O(m+n)

There are more efficient algorithms to search pattern once the suffix array is built. In fact there is a O(m) suffix array based algorithm to search a pattern. We will soon be discussing efficient algorithm for search.
Applications of Suffix Array
Suffix array is an extremely useful data structure, it can be used for a wide range of problems. Following are some famous problems where Suffix array can be used.
1) Pattern Searching
2) Finding the longest repeated substring
3) Finding the longest common substring
4) Finding the longest palindrome in a string

See this for more problems where Suffix arrays can be used.
This post is a simple introduction. There is a lot to cover in Suffix arrays. We have discussed a O(nLogn) algorithm for Suffix Array construction here. We will soon be discussing more efficient suffix array algorithms.
References:
http://www.stanford.edu/class/cs97si/suffix-array.pdf
http://en.wikipedia.org/wiki/Suffix_array