Checksum Validation

Code

#include <stdio.h>

int validate_checksum(int *mem, int n) {
    int checksum = 0;
    int *end = mem + n - 1;

    // XOR all bytes except last
    for (int *ptr = mem; ptr < end; ptr++) {
        checksum ^= *ptr;
    }

    // Mask once at the end for 8-bit checksum
    return ((checksum & 0xFF) == (*end & 0xFF)) ? 1 : 0;
}

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

    int result = validate_checksum(arr, n);
    printf("%d", result);

    return 0;
}

Solving Approach