How to store a very large number of more than 100 digits in C++
Given an integer N in form of string str consisting of more than 100 digits, the task is to store the value for performing an arithmetic operation and print the given integer.
Input: str = “54326789013892014531903492543267890138920145319034925432678901389201”
Input: str = “7890138920145319034925432678907890138920145319034925432678901903492543267890”
No data type is present in C++ to store 10100. So, the idea is to use get the input as string (as string can be of any length) and then convert this string into an array of digits of the length same as the length of string. Storing the big integer into an integer array will help to perform some basic arithmetic on that number.
Below are the steps:
- Take the large number as input and store it in a string.
- Create an integer array arr of length same as the string size.
- Iterate over all characters (digits) of string str one by one and store that digits in the corresponding index of the array arr
arr[i] = str[i] – ‘0’;
// Here ‘0’ represents the digit 0, and
// str[i] – ‘0’ = ASCII(str[i]) – ASCII(‘0’) = ASCII(str[i] – 48
- Using the above step, we can store very very large number for doing any arithmetic operations.
Below is the implementation of the above approach:
Time Complexity: O(K), K is the number of digits in the number
Auxiliary Space: O(K), K is the number of digits in the number