Sliding Window Sum

Code

#include <stdio.h>

void sliding_window_sum(int arr[], int n, int k) {
    int step = n-k+1;
    int window = 0;
    // calculate first window
    for (int i=0; i <k; i++){
        window += arr[i];
    }
    printf("%d ", window);
    // each sliding window = prev window - left most + right most
    for (int i =1; i < step; i++){
        int next = window - arr[i-1] + arr[i-1+k];
        window = next;
        printf("%d ", next);
    }

}

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

    sliding_window_sum(arr, n, k);
    return 0;
}

Solving Approach