Move all zeroes to end of array in C++

Given array with multiple zeroes in it. We have to move all the zeroes in the array to the end. Let's see an example.

Input

arr = [4, 5, 0, 3, 2, 0, 0, 0, 5, 0, 1]

Output

4 5 3 2 5 1 0 0 0 0 0

Algorithm

• Initialise the array.

• Initialise an index to 0.

• Iterate over the given array.

  • If the current element is not zero, then update the value at the index with the current element.

  • Increment the index.

• Write a loop that iterates from the above index to n

  • Update all the elements to 0.

Implementation

Following is the implementation of the above algorithm in C++

#include <bits/stdc++.h>
using namespace std;
void moveZeroesToEnd(int arr[], int n) {
   int index = 0;
   for (int i = 0; i < n; i++) {
      if (arr[i] != 0) {
         arr[index++] = arr[i];
      }
   }
   while (index < n) {
      arr[index++] = 0;
   }
}
int main() {
   int arr[] = {4, 5, 0, 3, 2, 0, 0, 0, 5, 0, 1};
   int n = 11;
   moveZeroesToEnd(arr, n);
   for (int i = 0; i < n; i++) {
      cout << arr[i] << " ";
   }
   cout << endl;
   return 0;
}

Output

If you run the above code, then you will get the following result.

4 5 3 2 5 1 0 0 0 0 0