再一道区间DP -- P4170 [CQOI2007]涂色

https://www.luogu.org/problemnew/show/P4170

一道简单的区间DP,注意读入

#include <bits/stdc++.h>
#define up(i,l,r) for(int i = (l);i <= (r); i++)
using namespace std;
int f[][];
char s[];
int main()
{
//    freopen("color.in","r",stdin);
    memset(f,0x7F,sizeof(f));
    scanf("%s",s + );
    int n = strlen(s + );
    up(i,,n) f[i][i] = ;
    up(L,,n - )
        for(int i = ,j = i + L; j <= n;i++,j++)
        {
            if(s[i] == s[j]) f[i][j] = min(f[i + ][j],f[i][j - ]);
            else up(k,i,j - ) f[i][j] = min(f[i][j],f[i][k] + f[k + ][j]);
        }
    printf("%d",f[][n]);
    return ;
}