POJ 2955 Brackets 区间DP 入门

if(s[i]=='('&&s[j]==')'||s[i]=='['&&s[j]==']')
dp[i][j]=dp[i+1][j-1]+2;
dp[i][j]=max{dp[i][k]+dp[k+1][j]};

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

int check(char a,char b)
{
if(a=='('&&b==')')
return 1;
if(a=='['&&b==']')
return 1;

return 0;
}

int main()
{
char str[111];
int dp[111][111],i,j,k,len;
while(scanf("%s",str)!=EOF)
{
if(!strcmp(str,"end"))
break;
len=strlen(str);
memset(dp,00,sizeof(dp));
for(k=1;i<len;k++)  ////表示区间长度，从0-len更新

{
for(i=0,j=k;j<len;i++,j++)
{
if(check(str[i],str[j]))
dp[i][j]=dp[i+1][j-1]+2;
for(int x=i;x<j;x++)  // //区间最值合并

{
dp[i][j]=max(dp[i][j],dp[i][x]+dp[x][j]);
}
}
}
printf("%d\n",dp[0][len-1]);
}
return 0;
}