# Double the first element and move zero to end in C++ Program

C++Server Side ProgrammingProgramming

In this tutorial, we are going to write a program that doubles the first element and moves all the zeroes to the end of the given array.

We have to double a number when there are tow the same elements in adjacent indices. After that, we have to add a zero to the array.

Move all the zeroes in the array to the end.

## Example

Let's see the code.

Live Demo

#include <bits/stdc++.h>
using namespace std;
void moveZeroesToEnd(int arr[], int n) {
int count = 0;
for (int i = 0; i < n; i++) {
if (arr[i] != 0) {
arr[count++] = arr[i];
}
}
while (count < n) {
arr[count++] = 0;
}
}
void updateAndRearrangeArray(int arr[], int n) {
if (n == 1) {
return;
}
for (int i = 0; i < n - 1; i++) {
if ((arr[i] != 0) && (arr[i] == arr[i + 1])) {
arr[i] = 2 * arr[i];
arr[i + 1] = 0;
i++;
}
}
moveZeroesToEnd(arr, n);
}
void printArray(int arr[], int n) {
for (int i = 0; i < n; i++)
cout << arr[i] << " ";
}
int main() {
int arr[] = { 2, 3, 3, 4, 0, 5, 5, 0 }, n = 7;
cout << "Given Array: ";
printArray(arr, n);
cout << endl;
updateAndRearrangeArray(arr, n);
cout << "Updated Array: ";
printArray(arr, n);
cout << endl;
return 0;
}

## Output

If you execute the above program, then you will get the following result.

Given Array: 2 3 3 4 0 5 5
Updated Array: 2 6 4 10 0 0 0

## Conclusion

If you have any queries in the tutorial, mention them in the comment section.