[区间dp] hdu 2476 string painter

#include<iostream>#include<cstdio>#include<string>#include<cstring>#include<cstdlib>#include<cmath>#include<algorithm>#include<set>#include<map>#include<vector>using namespace std;const int INF=0x3f3f3f3f;const int MAXN = 105;char s1[MAXN],s2[MAXN];int dp[MAXN][MAXN];int n;int main(){    while(~scanf("%s%n%s",s1+1,&n,s2+1))    {        memset(dp,0,sizeof dp);        for(int len=1;len<=n;len++)        {            for(int i=1;i+len-1<=n;i++)            {                int j=i+len-1;                //dp[i,j]:该区间从空白开始刷成s2[i,j]最少的次数                //看s2[i]要刷多少个，取最优                dp[i][j]=dp[i+1][j]+1;//先只刷i位置                for(int k=i+1;k<=j;k++)//先将[i,k-1]刷成s2[i]，再刷[k+1,j]                    if(s2[k]==s2[i])                        dp[i][j]=min(dp[i][j],dp[i+1][k-1]+dp[k][j]);            }        }        int ans[MAXN];        memset(ans, 0x3f, sizeof ans);        ans[0]=0;        ans[1]=(s1[1]!=s2[1]);        for(int i=2;i<=n;i++)        {            if(s1[i]==s2[i]) {ans[i]=ans[i-1];continue;}            //此时i处必须涂一次，考虑涂[k+1,i]，不同的k中的最优解            ans[i]=dp[1][i];            for(int k=1;k<i;k++)//分别刷[1,k和[k+1,i]                ans[i]=min(ans[i],ans[k]+dp[k+1][i]);        }        cout<<ans[n]<<endl;    }    return 0;}