[CQOI 2007] 涂色

[题目链接]

         https://www.lydsy.com/JudgeOnline/problem.php?id=1260

[算法]

        区间DP

[代码]

        

#include<bits/stdc++.h>
using namespace std;
#define MAXN 55

int i,j,k,t,len;
int f[MAXN][MAXN];
char s[MAXN];

int main() 
{
        
        scanf("%s",s + 1);
        len = strlen(s + 1);
        memset(f,0x3f,sizeof(f));
        for (i = 1; i <= len; i++) f[i][i] = 1;
        for (i = 2; i <= len; i++)
        {
                for (j = 1; j <= len - i + 1; j++)
                {
                        k = j + i - 1;
                        if (s[j] == s[k])
                        {
                                f[j][k] = min(f[j + 1][k],f[j][k - 1]);    
                                f[j][k] = min(f[j][k],f[j + 1][k - 1] + 1);
                        } else
                        {
                                for (t = j; t < k; t++)
                                        f[j][k] = min(f[j][k],f[j][t] + f[t + 1][k]);
                        }
                } 
        }
        printf("%d
",f[1][len]);
        
        return 0;
    
}