poj 1159 -- Palindrome

 1 /*======================================================================
 2  *           Author :   kevin
 3  *         Filename :   Palindrome.cpp
 4  *       Creat time :   2014-09-25 10:31
 5  *      Description :
 6 ========================================================================*/
 7 #include <iostream>
 8 #include <algorithm>
 9 #include <cstdio>
10 #include <cstring>
11 #include <queue>
12 #include <cmath>
13 #define clr(a,b) memset(a,b,sizeof(a))
14 #define M 5005
15 using namespace std;
16 char str1[M];
17 short int dp[M][M];
18 int main(int argc,char *argv[])
19 {
20     int n;
21     while(scanf("%d",&n) != EOF){
22         scanf("%s",str1);
23         for(int i = 1; i <= n; i++){
24             for(int j = 1; j <= n; j++){
25                 if(str1[i-1] == str1[n-j]){
26                     dp[i][j] = dp[i-1][j-1] + 1;
27                 }
28                 else{
29                     dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
30                 }
31             }
32         }
33         printf("%d\n",n - dp[n][n]);
34     }
35     return 0;
36 }