poj 1159 dp回文串

题意：添加最少的字符使之成为回文串

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<queue>
using namespace std;
const int maxn=5001;
int n,m,t;
short dp[maxn][maxn];
char s[maxn];
int main()
{
    int i,j,k;
    #ifndef ONLINE_JUDGE
    freopen("1.in","r",stdin);
    #endif
        int len=0;
        scanf("%d",&len);
        scanf("%s",s);
        for(i=0;i<len;i++)  dp[i][i]=0;
        for(k=1;k<len;k++)
        {
            for(i=0;i+k<=len;i++)
            {
                int j=k+i;
                if(s[i]==s[j])  dp[i][j]=dp[i+1][j-1];
                else dp[i][j]=min(dp[i+1][j],dp[i][j-1])+1;
            }
        }
        printf("%d
",dp[0][len-1]);
    return 0;
}