C Exercises: Remove duplicates from an array of integers

Last update on December 20 2024 13:07:31 (UTC/GMT +8 hours)

Write a C program to remove duplicates from a given array of integers.

C Code:

#include <stdio.h>
#include <stdlib.h>
static int remove_duplicates(int* nums, int arr_size)
{
    if (arr_size <= 1) {
        return arr_size;
    }

    int i = 0, j, count = 1;
    while (i < arr_size) {
        for (j = i + 1; j < arr_size && nums[i] == nums[j]; j++) {}
        if (j < arr_size) {
            nums[count++] = nums[j];
        }
        i = j;
    }

    return count;
}

int main(void)
{
    int nums[] = {1,1,2,3,4,4,5,6,6,6};    
    int size = sizeof(nums)/sizeof(nums[0]);
    printf("Original array:\n");
    int i;
    for (i = 0; i < size; i++) {
        printf("%d ", nums[i]);
    }
    int count = remove_duplicates(nums, size);
    printf("\nAfter removing duplicates from the above sorted array:\n");
    for (i = 0; i < count; i++) {
        printf("%d ", nums[i]);
    }
    printf("\n");
    return 0;
}

Sample Output:

Original array:
1 1 2 3 4 4 5 6 6 6 
After removing duplicates from the above sorted array:
1 2 3 4 5 6 

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