Usaco section 2.1: Healthy Holsteins

I haven't written it for a long time. I can't even write a DFS.

 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 }

 

Usaco section 2.1: Healthy Holsteins