poj 1141 Brackets Sequence ( 区间dp+输出方案 )

http://blog.****.net/cc_again/article/details/10169643

http://blog.****.net/lijiecsu/article/details/7589877

如果有空串要用gets，scanf不能处理空串

#include <iostream>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <cctype>
#include <vector>
#include <iterator>
#include <set>
#include <map>
#include <sstream>
using namespace std;

#define mem(a,b) memset(a,b,sizeof(a))
#define pf printf
#define sf scanf
#define spf sprintf
#define pb push_back
#define debug printf("!\n")
#define INF 10000
#define MAX(a,b) a>b?a:b
#define blank pf("\n")
#define LL long long
#define ALL(x) x.begin(),x.end()
#define INS(x) inserter(x,x.begin())
#define pqueue priority_queue

const int MAXN =  + ;

int n,m;

int dp[][],path[][];
char a[];

bool match(int i,int j)
{
    return (a[i]=='(' && a[j]== ')') || (a[i]=='[' && a[j]== ']');
}
void print(int i,int j)
{
    if(i>j) return;
    if(i == j)
    {
        if(a[i] == '(' || a[i]== ')')
            pf("()");
        else
            pf("[]");
        return;
    }
    if(path[i][j] == -)
    {
        pf("%c",a[i]);
        print(i+,j-);
        pf("%c",a[j]);
        return;
    }
    else
    {
        print(i,path[i][j]);
        print(path[i][j]+,j);
    }
}

int main()
{
    int i,j;
    while(gets(a))
    {
        n = strlen(a);
        mem(dp,);
        mem(path,);
        for(i=;i<n;i++)
            dp[i][i]=;
        for(int l = ;l<n;l++)
        {
            for(i=;i<n-l;i++)
            {
                j = i+l;
                dp[i][j] = <<;
                if(match(i,j) && dp[i+][j-] < dp[i][j])
                {
                    dp[i][j] = dp[i+][j-];
                    path[i][j] = -;
                }

                for(int k =i;k<j;k++)
                {
                    if(dp[i][k]+dp[k+][j] < dp[i][j])
                    {
                        dp[i][j] = dp[i][k]+dp[k+][j];
                        path[i][j] = k;
                    }
                }
            }
        }
        print(,n-);
        blank;
    }
    return ;
}