sumofsub

#include <iostream>#include <cstdlib>#include <cstring>using namespace std;int x[256], w[256];int M, n;void print(int n){int i;for (i = 1; i <= n; i++){if (x[i]){cout << w[i] << ' ';}}cout << endl;}void sumofsub(int s, int k, int r){if (k > n)return;x[k] = 1;if (s + w[k] == M)print(k);else if (s + w[k] + w[k + 1] <= M)sumofsub(s + w[k], k + 1, r - w[k]);x[k] = 0;if (s + r - w[k] >= M && s + w[k + 1] <= M)sumofsub(s, k + 1, r - w[k]);}int main(){int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};int W = 0;int i;M = 20;n = sizeof(a) / sizeof(int);memset(w, 0, sizeof(w));for (i = 1; i <= n; i++){w[i] = a[i - 1];W += w[i];}sumofsub(0, 1, W);cin.get();return 0;}