sdut2536字母哥站队(dp)

简单DP  说是简单 还是推了好一会 推出来觉得好简单

保留当前i的最小值 dp[i] = min(dp[i],dp[j]+i-j-1) j<i

 1 #include <iostream>

 2 #include<cstdio>

 3 #include<cstring>

 4 #include<algorithm>

 5 #include<stdlib.h>

 6 using namespace std;

 7 #define INF 0xfffffff

 8 char s[5010];

 9 int w[500][500],dp[5010];

10 int main()

11 {

12     int i,j,k,n;

13     char a,b;

14     while(cin>>s)

15     {

16         memset(dp,0,sizeof(dp));

17         memset(w,0,sizeof(w));

18         cin>>n;

19         k = strlen(s);

20         for(i = 1 ; i <= n ; i++)

21         {

22             cin>>a>>b;

23             w[a][b] = 1;

24             w[b][a] = 1;

25         }

26         dp[0] = 0;

27         for(i = 1 ; i  < k ; i++)

28         {

29             dp[i] = i;

30             for(j = i-1 ; j >= 0 ; j--)

31             if(!w[s[i]][s[j]])

32             dp[i] = min(dp[i],dp[j]+i-j-1);

33         }

34         int ans = INF;

35         for(i =0 ; i < k ; i++)

36         ans = min(ans,dp[i]+k-i-1);

37         cout<<ans<<endl;

38     }

39     return 0;

40 }

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