递归算法---0-1背包问题（面试宝典）
/** *正整数n,m,从数列1、2、3、...、n中随意取几个数。使其和等于m *要求将其中所有可能的组合列出来 */ #include <stdio.h>#include <string.h>#include <stdlib.h>int *out;int out_size;void bag(int n, int m){ int i; if (n < 1 || m < 1 || (n == 1 && m != 1)) return; if (m == n) { out[n] = 1; for (i = 1; i <= out_size; i++) { if (out[i]) printf("%d ", i); } printf("\n"); out[n] = 0; } bag(n - 1, m); out[n] = 1; bag(n - 1, m - n); out[n] = 0;}int main(){ int n, m; printf("Please input two num(n,m):"); scanf("%d%d", &n, &m); if (n > m) n = m; out_size = n; out = (int *)malloc((n + 1) * sizeof(int)); memset(out, 0, (n + 1) * sizeof(int)); bag(n, m); free(out); return 0;}?