﻿ C Program: Shift even numbers before odd in an array

# C Exercises: Create new array from a given array of integers shifting all even numbers before all odd numbers

## C-programming basic algorithm: Exercise-73 with Solution

Write a C program to create an array from a given array of integers shifting all even numbers before all odd numbers.

C Code:

``````#include <stdio.h>
#include <stdlib.h>

// Function prototype for 'print_array'
void print_array(int parray[], int size);

int main(void){
int arr_size;

// Declaration and initialization of an integer array 'a1'
int a1[] = {1, 2, 5, 3, 5, 4, 6, 9, 11};
arr_size = sizeof(a1)/sizeof(a1[0]);

// Printing the elements of the original array 'a1'
printf("Elements in original array are: ");
print_array(a1, arr_size);

// Declaration of 'size' and 'index' variables
int size = arr_size, index = 0;

// Loop to iterate through the elements of 'a1'
for (int i = 0; i < size; i++)
{
// If the current element is even, swap it with the element at 'index'
if (a1[i] % 2 == 0)
{
int temp = a1[index];
a1[index] = a1[i];
a1[i] = temp;

index++;
}
}

// Printing the elements of the modified array 'a1'
printf("\nElements in new array are: ");
print_array(a1, arr_size);
}

// Definition of the 'print_array' function
void print_array(int parray[], int size)
{
int i;
// Loop to print the elements of the array
for( i = 0; i < size - 1; i++)
{
printf("%d, ", parray[i]);
}
// Printing the last element
printf("%d ", parray[i]);
printf("\n");
}
``````

Sample Output:

```Elements in original array are: 1, 2, 5, 3, 5, 4, 6, 9, 11

Elements in new array are: 2, 4, 6, 3, 5, 1, 5, 9, 11
```

Pictorial Presentation:

Flowchart:

C Programming Code Editor:

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