This is my code, it works good on the sample test, but I get WA1

#include <stdio.h>

unsigned int w[20], s, i, n, max, h, j, k, r[20], l[20];
bool a[50001]={1}, u[50001][20];

int main (void){
    scanf("%u", &n);
    for(i = 0; i < n; i++){
        scanf("%u", &w[i]);
        h += w[i];
    }
    for(i = 1; i <= h/2; i++)
        for(j = 0; j < n; j++){
            if(u[i - w[j]][j] == 0 && a[i - w[j]] && i - w[j] >= 0){
                a[i]++;
                for(k = 0; k < n; k++)
                    u[i][k] = u[i-w[j]][k];
                u[i][j]++;
                max = i;
                j = n;
            }
        }
    printf("%i", h - 2*max);
    return 0;
}