uva10118
題意：給定4堆糖果，每堆有n顆，有一個最多可以裝5個糖果的袋子，每次選擇一堆糖果，把最頂上的一顆拿到袋子里，如果袋子里有兩顆一樣的糖果就拿走。問最多可拿幾對。
分析：枚舉每次可以從4堆中任意一堆拿走。
#include<iostream> #include<algorithm> #include<math.h> #include<string.h> #include<stdio.h> #include<string> #include<vector> #include<queue> #include<map> #include<sstream> #include<cassert> #include<set> using namespace std; typedef long long ll; const int maxn = 40 + 10; int d[maxn][maxn][maxn][maxn]; int vis[maxn],n; int mp[maxn][4]; int top[4]; int dp(int k) {int &ans = d[top[0]][top[1]][top[2]][top[3]];if (ans != -1)return ans;ans = 0;if (k >= 5)return ans;for (int i = 0; i < 4; i++) {if (top[i] == n)continue;++top[i];if (vis[mp[top[i]][i]]) {vis[mp[top[i]][i]] = 0;ans = max(ans, dp(k - 1) + 1);vis[mp[top[i]][i]] = 1;}else {vis[mp[top[i]][i]] = 1;ans = max(ans, dp(k+1));vis[mp[top[i]][i]] = 0;}--top[i];}return ans; } int main() {while (cin >> n && n) {for (int i = 1; i <= n; i++) {for (int j = 0; j < 4; j++)cin >> mp[i][j];}memset(vis, 0, sizeof(vis));memset(d, -1, sizeof(d));memset(top, 0, sizeof(top));cout << dp(0) << endl;}return 0; }?
總結
