/*
 * File: ssum.c
 * Purpose: Solves the SSUM problem naively.
 * Compilation: gcc -o ssum ssum.c
 * Execution: ./ssum
 * Author: San Skulrattanakulchai
 */

#include <stdio.h>
#include <stdbool.h>

static bool solution = false;

void check(int i, int sum, int a[], int size, int target) {
    if (i < size) {
        check(i+1, sum, a, size, target);
        check(i+1, sum + a[i], a, size, target);
    } else if (sum == target)
        solution = true;
}

void ssum(int a[], int size, int target) {
    solution = false;
    check(0, 0, a, size, target);
    printf("%s\n", solution ? "true" : "false");
}

int main(int argc, char **argv) {
    int a[] = { 7, 3, 1, 5, 6 };
    ssum(a, 5, 12);  /* => true */
    ssum(a, 5, 24);  /* => false */
}