POJ 2955 Brackets

//#include <bits/stdc++.h>
#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
char s[128];
int dp[128][128];
int n;

int dfs(int l,int r)
{
    if(dp[l][r]!=-1)
        return dp[l][r];
    if(l==r)
        return dp[l][r]=0;
    if(l+1==r){
        if(s[l]=='('&&s[r]==')')
            return dp[l][r]=2;
        if(s[l]=='['&&s[r]==']')
            return dp[l][r]=2;
    }
    //int maxx=0;
    if(s[l]=='('&&s[r]==')')
        //maxx=max(maxx,2+rec(l+1,r-1));
        dp[l][r] = max(dp[l][r], dfs(l + 1, r - 1) + 2);
    if(s[l]=='['&&s[r]==']')
       // maxx=max(maxx,2+rec(l+1,r-1));
        dp[l][r] = max(dp[l][r], dfs(l + 1, r - 1) + 2);
    for(int k=l;k<=r-1;++k)
        //maxx=max(maxx,rec(l,k)+rec(k+1,r));
        dp[l][r] = max(dp[l][r], dfs(l, k) + dfs(k + 1, r));
    return dp[l][r];
}

int main()
{
    while(scanf("%s",s)==1){
        if(s[0]=='e')
            break;
        memset(dp,-1,sizeof(dp));
        n=strlen(s);
        printf("%d\n",dfs(0,strlen(s)-1));
    }
    return 0;
}