Sliding Window Sum

Code

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

int* sliding_window_sum(int arr[], int n, int k) {

   int* result = (int*)malloc((n-k+1) * sizeof(int));

    int sum=0;
    for(int i=0;i<k;i++){
        sum+=arr[i];
        result[0]=sum;
    }

    for(int i=k;i<n;i++){
        sum+=arr[i]-arr[i-k];
        result[i-k+1]=sum;
    }
    return result;
}

int main() {
    int n, k, arr[100];
    scanf("%d %d", &n, &k);
    for (int i = 0; i < n; i++) scanf("%d", &arr[i]);

    int *sum=sliding_window_sum(arr, n, k);
    for(int i=0;i<=n-k;i++){
        printf("%d ",sum[i]);
    }
    free(sum);
}

Solving Approach