uva 10118，记忆化搜索

这个题debug了长达3个小时，acm我不能放弃，我又回来了的第一题！

 

一开始思路正确，写法不行，结果越改越乱

看了网上某神的代码，学习了一下

coding+debug：4小时左右，记忆化搜索+dp类型第一题

/*
 * Author:  Bingo
 * Created Time:  2015/3/2 21:23:20
 * File Name: uva10118.cpp
 */
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <time.h>
using namespace std;
const int maxint = -1u>>1;
int dp[45][45][45][45];
int a[4][45];
int f[5];
int n;
int ans;
int ok(int i,int j,int p,int q){
    int m[500];
    memset(m,0,sizeof(m));
    int top=0;
    for (int t=0;t<i;t++)
        m[top++]=a[0][t];
    for (int t=0;t<j;t++)
        m[top++]=a[1][t];
    for (int t=0;t<p;t++)
        m[top++]=a[2][t];
    for (int t=0;t<q;t++)
        m[top++]=a[3][t];
    sort(m,m+top);
    int cnt=0,tans=0;
    for (int t=0;t<top;){
        if (m[t]==m[t+1]){
            tans++;
            t+=2;
        }else {
            cnt++;
            t++;
        }
    }
    if (cnt<=5){
        ans=max(ans,tans);
        return 1;
    }
    return 0;
}
int dfs(int i,int j,int p,int q){
    if (i==n&&j==n&&p==n&&q==n) return 0;
    if (i<n){
        i++;
        if(ok(i,j,p,q)) {
            if (dp[i][j][p][q]){
                ans=max(ans,dp[i][j][p][q]);
                dp[i][j][p][q]=ans;
            }else {dp[i][j][p][q]=ans;dfs(i,j,p,q);}
        }
    }
    if (j<n){
        j++;
        if(ok(i,j,p,q)) {
            if (dp[i][j][p][q]){
                ans=max(ans,dp[i][j][p][q]);
                dp[i][j][p][q]=ans;
            }else {dp[i][j][p][q]=ans;dfs(i,j,p,q);}
        }
    }
    if (p<n){
        p++;
        if(ok(i,j,p,q)) {
            if (dp[i][j][p][q]){
                ans=max(ans,dp[i][j][p][q]);
                dp[i][j][p][q]=ans;
            }else {dp[i][j][p][q]=ans;dfs(i,j,p,q);}
        }
    }
    if (q<n){
        q++;
        if(ok(i,j,p,q)) {
            if (dp[i][j][p][q]){
                ans=max(ans,dp[i][j][p][q]);
                dp[i][j][p][q]=ans;
            }else {dp[i][j][p][q]=ans;dfs(i,j,p,q);}
        }
    }
}
int main () {
    while(cin>>n&&n){
        for (int i=0;i<n;i++) {
            cin >> a[0][i]>>a[1][i]>>a[2][i]>>a[3][i];
        }
        memset(dp,0,sizeof(dp));
        ans=0;
        memset(f,0,sizeof(f));
        //ok(3,3,3,3);
        dfs(0,0,0,0);
        cout << ans<<endl;
    }
    return 0;
}