区间dp括号匹配问题 POJ2955

//#include<bits/stdc++.h>
//#include <unordered_map>
//#include<unordered_set>
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<set>
#include<climits>
#include<queue>
#include<cmath>
#include<stack>
#include<map>
using namespace std;
#define LL long long
#define ULL unsigned long long
#define MT(a,b) memset(a,b,sizeof(a))
const int INF  =  0x3f3f3f3f;
const int ONF  = -0x3f3f3f3f;
const int O    =  1e5;
const int mod  =  1e9+7;
const int maxn =  1e2+5;
const int N    =  1e9+5;
const double PI  =  3.141592653589;
const double E   =  2.718281828459;


int main()
{
    char s[maxn];
    while(scanf("%s",s)&&strcmp(s,"end"))
    {
        int dp[maxn][maxn]; MT(dp,0);
        int n = strlen(s);
        for(int len= 2; len<= n; len++)
        {
            for(int i=0;i<n;i++)
            {
                int j = i + len - 1;
                if((s[i]=='('&&s[j]==')')||(s[i]=='['&&s[j]==']'))
                    dp[len][i] = dp[len-2][i+1] + 2;
                for(int k=1;k<len;k++)
                    dp[len][i] = max(dp[len][i], dp[k][i]+dp[len-k][k+i]);
            }
        }
        printf("%d\n",dp[n][0]);
    }
    return 0;
}