> 代码如下～
> #include <iostream>
> #include <cstdio>
> #include <cstring>
> using namespace std;
> 
> const int N = 110;
> const int INF = 65536;
> 
> char str[N];
> int f[N][N], act[N][N];
> bool finish[N][N];
> 
> void Outchar(char c)
> {
>     switch(c)
>     {
>         case '(': printf(")"); break;
>         case ')': printf("("); break;
>         case '[': printf("]"); break;
>         case ']': printf("["); break;
>     }
> }
> 
> bool Yes(char c1, char c2)
> {
>     if(c1=='(' && c2==')')  return true;
>     if(c1=='[' && c2==']')  return true;
>     return false;
> }
> 
> void Dp(int l, int r)
> {
>     int i;
>     if(finish[l][r])  return;
>     if(l == r)
>     {
>         f[l][r] = 1;
>         return;
>     }
>     if(l > r)
>     {
>         f[l][r] = 0;
>         return;
>     }
>     f[l][r] = INF;
>     if(Yes(str[l], str[r]))
>     {
>         Dp(l+1, r-1);
>         if(f[l+1][r-1] < f[l][r])
>         {
>             f[l][r] = f[l+1][r-1];
>             act[l][r] = 0;
>         }
>     }
>     for(i = l; i < r; i++)
>     {
>         Dp(l, i);
>         Dp(i+1, r);
>         if(f[l][i]+f[i+1][r] < f[l][r])
>         {
>             f[l][r] = f[l][i]+f[i+1][r];
>             act[l][r] = i;
>         }
>     }
>     finish[l][r] = true;
> }
> 
> void Print(int l, int r)
> {
>     if(l == r)
>     {
>         switch(str[l])
>         {
>             case '(': printf("()"); break;
>             case ')': printf("()"); break;
>             case '[': printf("[]"); break;
>             case ']': printf("[]"); break;
>         }
>         return;
>     }
>     if(l > r)  return;
>     if(act[l][r] == 0)
>     {
>         printf("%c", str[l]);
>         Print(l+1, r-1);
>         printf("%c", str[r]);
>     }
>     else
>     {
>         Print(l, act[l][r]);
>         Print(act[l][r]+1, r);
>     }
> }
> 
> int main()
> {
>     int len;
>     char s[N];
>     scanf("%s", s);
>     len = strlen(s);
>     if(len == 0)
>     {
>         printf("\n");
>         return 0;
>     }
>     for(int i=0; i < len; i++)  str[i+1] = s[i];
>     memset(act, -1, sizeof(act));
>     memset(finish, false, sizeof(finish));
>     Dp(1, len);
>     Print(1, len);
>     printf("\n");
>     return 0;
> }
很鸡巴正常！我常遇到，你做题是不是太少了？