hdoj 1015 暴力dfs

//我自己sb 在dfs回去的时候少加了几个return 导致tle 就有点气

// 题目就不列了 就是暴力dfs 很easy 作为一个新手也可以自己码出来

#include<iostream>#include<string>#include<cmath>#include<cstring>#include<algorithm>using namespace std;double n;int sz;double sum;int word[13];bool mark[13];int ans[6];bool flag;bool cmp(int a, int b) {return a > b;}void dfs(int k) {if (!flag) return;if (k > 5) {//cout << sum << " ";sum = ans[1] - ans[2] * ans[2] + ans[3] * ans[3] * ans[3] - ans[4] * ans[4] * ans[4] * ans[4] + ans[5] * ans[5] * ans[5] * ans[5] * ans[5];if (sum == n) {for (int i = 1; i <= 5; i++) {//	cout << ans[i] << endl;char x = ans[i] + 'A' -1;cout << x;}cout << endl;flag = 0;}return;}for (int i = 1; i <= sz; i++) {if (!mark[i]) {mark[i] = 1;ans[k] = word[i];dfs(k + 1);mark[i] = 0;}}}int main(){string s;while (cin >> n) {flag = 1;cin >> s;memset(mark, 0, sizeof(mark));memset(ans, 0, sizeof(ans));memset(word, 0, sizeof(word));if (s == "END") break;sz = s.size();for (int i = 0; i < sz; i++) {word[i + 1] = s[i] - 'A' + 1;}sort(word+1, word+sz+1,cmp);//	for (int i = 1; i <= sz; i++)//		cout << word[i] << " ";dfs(1);if (flag) cout << "no solution" << endl;}return 0;}