# Generate first K multiples of N using Bitwise operators

• Difficulty Level : Expert
• Last Updated : 02 Nov, 2021

Given an integer N, the task is to print the first K multiples of N using Bitwise Operators.

Examples:

Input: N = 16, K = 7
Output:
16 * 1 = 16
16 * 2 = 32
16 * 3 = 48
16 * 4 = 64
16 * 5 = 80
16 * 6 = 96
16 * 7 = 112
Input: N = 7, K = 10
Output:
7 * 1 = 7
7 * 2 = 14
7 * 3 = 21
7 * 4 = 28
7 * 5 = 35
7 * 6 = 42
7 * 7 = 49
7 * 8 = 56
7 * 9 = 63
7 * 10 = 70

Approach:

Follow the steps below to solve the problem:

• Iterate up to K.
• For each iteration, print current value of N.
• Then, calculate the sum of 2i for every ith set bit of N. Add this sum to N and repeat from the step above.

Below is the implementation of the above approach:

## C++

 `// C++ program to implement` `// the above approach` `#include ` `using` `namespace` `std;`   `// Function to print the first K` `// multiples of N` `void` `Kmultiples(``int` `n, ``int` `k)` `{` `    ``int` `a = n;`   `    ``for` `(``int` `i = 1; i <= k; i++) {`   `        ``// Print the value of N*i` `        ``cout << n << ``" * "` `<< i << ``" = "` `             ``<< a << endl;` `        ``int` `j = 0;`   `        ``// Iterate each bit of N and add` `        ``// pow(2, pos), where pos is the` `        ``// index of each set bit` `        ``while` `(n >= (1 << j)) {`   `            ``// Check if current bit at` `            ``// pos j is fixed or not` `            ``a += n & (1 << j);`   `            ``// For next set bit` `            ``j++;` `        ``}` `    ``}` `}`   `// Driver Code` `int` `main()` `{` `    ``int` `N = 16, K = 7;`   `    ``Kmultiples(N, K);`   `    ``return` `0;` `}`

## Java

 `// Java program to implement` `// the above approach` `import` `java.util.*;` `class` `GFG{`   `// Function to print the first K` `// multiples of N` `static` `void` `Kmultiples(``int` `n, ``int` `k)` `{` `    ``int` `a = n;`   `    ``for` `(``int` `i = ``1``; i <= k; i++)` `    ``{`   `        ``// Print the value of N*i` `        ``System.out.print(n+ ``" * "` `+  i+ ``" = "` `             ``+ a +``"\n"``);` `        ``int` `j = ``0``;`   `        ``// Iterate each bit of N and add` `        ``// Math.pow(2, pos), where pos is the` `        ``// index of each set bit` `        ``while` `(n >= (``1` `<< j)) ` `        ``{`   `            ``// Check if current bit at` `            ``// pos j is fixed or not` `            ``a += n & (``1` `<< j);`   `            ``// For next set bit` `            ``j++;` `        ``}` `    ``}` `}`   `// Driver Code` `public` `static` `void` `main(String[] args)` `{` `    ``int` `N = ``16``, K = ``7``;`   `    ``Kmultiples(N, K);` `}` `}`   `// This code is contributed by Rohit_ranjan`

## Python3

 `# Python3 program to implement ` `# the above approach ` `          `  `# Function to print the first K` `# multiples of N` `def` `Kmultiples(n, k):` `    `  `    ``a ``=` `n` `    `  `    ``for` `i ``in` `range``(``1``, k ``+` `1``):` `        `  `        ``# Print the value of N*i` `        ``print``(``"{} * {} = {}"``.``format``(n, i, a))` `        ``j ``=` `0` `        `  `        ``# Iterate each bit of N and add` `        ``# pow(2, pos), where pos is the` `        ``# index of each set bit` `        ``while``(n >``=` `(``1` `<< j)):` `            `  `            ``# Check if current bit at` `            ``# pos j is fixed or not` `            ``a ``+``=` `n & (``1` `<< j)` `            `  `            ``# For next set bit ` `            ``j ``+``=` `1` `            `  `# Driver Code` `N ``=` `16` `K ``=` `7`   `Kmultiples(N, K)`   `# This code is contributed by Shivam Singh`

## C#

 `// C# program to implement` `// the above approach` `using` `System;`   `class` `GFG{`   `// Function to print the first K` `// multiples of N` `static` `void` `Kmultiples(``int` `n, ``int` `k)` `{` `    ``int` `a = n;`   `    ``for``(``int` `i = 1; i <= k; i++)` `    ``{` `        `  `        ``// Print the value of N*i` `        ``Console.Write(n + ``" * "` `+ i + ` `                          ``" = "` `+ a + ``"\n"``);` `        ``int` `j = 0;`   `        ``// Iterate each bit of N and add` `        ``// Math.Pow(2, pos), where pos is` `        ``//  the index of each set bit` `        ``while` `(n >= (1 << j)) ` `        ``{` `            `  `            ``// Check if current bit at` `            ``// pos j is fixed or not` `            ``a += n & (1 << j);`   `            ``// For next set bit` `            ``j++;` `        ``}` `    ``}` `}`   `// Driver Code` `public` `static` `void` `Main(String[] args)` `{` `    ``int` `N = 16, K = 7;`   `    ``Kmultiples(N, K);` `}` `}`   `// This code is contributed by Amit Katiyar`

## Javascript

 ``

Output:

```16 * 1 = 16
16 * 2 = 32
16 * 3 = 48
16 * 4 = 64
16 * 5 = 80
16 * 6 = 96
16 * 7 = 112```

Time Complexity: O(Klog2N)
Auxiliary Space: O(1)

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