URAL 1152. False Mirrors(DP)

题目链接

理解了题意之后，就不难了。。状态压缩+暴力.

 1 #include <cstring>

 2 #include <cstdio>

 3 #include <string>

 4 #include <iostream>

 5 #include <algorithm>

 6 #include <vector>

 7 #include <queue>

 8 #include <cmath>

 9 using namespace std;

10 int dp[1<<20];

11 int sum[1<<20];

12 int p[101];

13 int minz;

14 int main()

15 {

16     int i,n,j,t1,t2,x;

17     scanf("%d",&n);

18     for(i = 0;i < n;i ++)

19     {

20         scanf("%d",&p[i]);

21     }

22     for(i = 0;i < 1<<n;i ++)

23     {

24         dp[i] = 10000000;

25         for(j = 0;j < n;j ++)

26         {

27             if(i&(1<<j))

28             sum[i] += p[j];

29         }

30     }

31     dp[(1<<n)-1] = 0;

32     for(i = (1<<n)-1;i >= 1;i --)

33     {

34         for(j = 0;j < n;j ++)

35         {

36             if(i&(1<<j))

37             {

38                 x = i - (1<<j);

39                 if(j-1 < 0)

40                 t1 = n-1;

41                 else

42                 t1 = j-1;

43                 if(j+1 >= n)

44                 t2 = 0;

45                 else

46                 t2 = j+1;

47                 if(x&(1<<t1))

48                 x -= 1<<t1;

49                 if(x&(1<<t2))

50                 x -= 1<<t2;

51                 dp[x] = min(dp[x],dp[i]+sum[x]);

52             }

53         }

54     }

55     printf("%d\n",dp[0]);

56     return 0;

57 }