nyojSticks

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>using namespace std;int a[64];int visit[64];int length, n;int cmp(int a, int b){return a > b;}int dfs(int pos, int num, int need){if (need == 0)//拼好了一个长度为length的木棍， 改变状态{need = length;pos = 0;}if (num == n)//拼接成功：所有的木棍都用了return 1;for (int i = pos; i < n; i++){if (visit[i] == 0 && need >= a[i]){visit[i] = 1;if (dfs(i + 1, num + 1, need - a[i]))return 1;visit[i] = 0;if (need == a[i])//如果大的拼接不成功，用小的来替换这个大的，是徒劳的return 0;if (need == length)//如果第一根木棍拼接不成功，则换掉第一根是没有意义的return 0;while (i + 1 < n && a[i + 1] == a[i])i++;//如果拼接不成功，不用搜相同长度的木棍}}return 0;}int main(){while (scanf("%d", &n) != EOF && n != 0){memset(a, 0, sizeof(a));memset(visit, 0, sizeof(visit));int sum = 0;for (int i = 0; i < n; i++){scanf("%d", &a[i]);sum += a[i];}sort(a, a + n, cmp);length = a[0];visit[0] = 1;for (; length <= sum; length++){if (sum % length != 0)   continue;    else {if (dfs(0, 1, length - a[0]))break;}}printf("%d\n", length);    }return 0;}