bzoj1260[CQOI2007]涂色paint

思路:区间dp,用f[i][j]表示区间[i,j]的答案,然后转移即可。

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<cmath>
 6 using namespace std;
 7  
 8 char s[100];
 9 int f[100][100];
10  
11 int main(){
12     scanf("%s",s+1);int n=strlen(s+1);
13     for (int i=1;i<=n;i++) f[i][i]=1;
14     for (int len=2;len<=n;len++){
15         for (int l=1;l<n;l++){
16             int r=l+len-1;if (r>n) break;
17             f[l][r]=min(f[l][r-1]+!(s[r]==s[r-1]),f[l+1][r]+!(s[l]==s[l+1]));
18             if (s[l]==s[r]) f[l][r]=min(f[l][r],min(f[l+1][r],f[l][r-1]));
19             if (l+1<=r-1)
20                 if (s[l]==s[r]) f[l][r]=min(f[l+1][r-1]+1,f[l][r]);
21             if (s[l]!=s[r]) for (int k=l; k<r; k++) f[l][r]=min(f[l][r],f[l][k]+f[k+1][r]);
22         }
23     }
24     printf("%d\n",f[1][n]);
25     return 0;
26 }
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posted @ 2016-10-09 20:52  DUXT  阅读(190)  评论(0编辑  收藏  举报