USACO Section 2.1: Healthy Holsteins

长久没写了，连个dfs都写不好了

 1 /*

 2 ID: yingzho2

 3 PROG: holstein

 4 LANG: C++

 5 */

 6 #include <iostream>

 7 #include <fstream>

 8 #include <string>

 9 #include <map>

10 #include <vector>

11 #include <set>

12 #include <algorithm>

13 #include <queue>

14 #include <cmath>

15 #include <list>

16 #include <cstring>

17 #include <cstdlib>

18 #include <limits>

19 #include <stack>

20 

21 using namespace std;

22 

23 ofstream fout ("holstein.out");

24 ifstream fin ("holstein.in");

25 

26 int V, G;

27 int target[30], input[30][30], cur[30], ans[30], tmp[30], size = 30;

28 

29 

30 bool check() {

31     for (int i = 0; i < V; ++i)

32         if (cur[i] < target[i]) return false;

33     return true;

34 }

35 

36 void dfs(int x, int sum) {

37     if (x > G) return;

38     for (int i = 0; i < V; ++i) cur[i] += input[x][i];

39     tmp[sum] = x;

40     if (check()) {

41         if (sum+1 < size) {

42             size = sum + 1;

43             for (int i = 0; i < V; ++i) ans[i] = tmp[i];

44         }

45     }

46     else dfs(x+1, sum+1);

47     for (int i = 0; i < V; ++i) cur[i] -= input[x][i];

48     dfs(x+1, sum);

49 }

50 

51 

52 int main()

53 {

54     fin >> V;

55     for (int i = 0; i < V; ++i) fin >> target[i];

56     fin >> G;

57     for (int i = 0; i < G; ++i) {

58         for (int j = 0; j < V; ++j) {

59             fin >> input[i][j];

60         }

61     }

62     dfs(0, 0);

63     fout << size << " ";

64     for (int i = 0; i < size-1; ++i) fout << ans[i]+1 << " ";

65     fout << ans[size-1]+1 << endl;

66     return 0;

67 }