Description In the German Lotto you have to select 6 numbers from the set {1,2,...,49}. A popular strategy to play Lotto - although it doesn‘t increase your chance of winning - is to select a subset S containing k (k > 6) of these 49 numbers, and then play several games Your job is to write a program that reads in the number k and the set S and then prints all possible games choosing numbers only from S. Input The input will contain one or more test cases. Each test case consists of one line containing several integers separated from each other by spaces. The first integer on the line will be the number k (6 < k < 13). Then k integers, specifying the set S, will Output For each test case, print all possible games, each game on one line. The numbers of each game have to be sorted in ascending order and separated from each other by exactly one space. The games themselves have to be sorted lexicographically, that means sorted Sample Input 7 1 2 3 4 5 6 7 8 1 2 3 5 8 13 21 34 0 Sample Output 1 2 3 4 5 6 1 2 3 4 5 7 1 2 3 4 6 7 1 2 3 5 6 7 1 2 4 5 6 7 1 3 4 5 6 7 2 3 4 5 6 7 1 2 3 5 8 13 1 2 3 5 8 21 1 2 3 5 8 34 1 2 3 5 13 21 1 2 3 5 13 34 1 2 3 5 21 34 1 2 3 8 13 21 1 2 3 8 13 34 1 2 3 8 21 34 1 2 3 13 21 34 1 2 5 8 13 21 1 2 5 8 13 34 1 2 5 8 21 34 1 2 5 13 21 34 1 2 8 13 21 34 1 3 5 8 13 21 1 3 5 8 13 34 1 3 5 8 21 34 1 3 5 13 21 34 1 3 8 13 21 34 1 5 8 13 21 34 2 3 5 8 13 21 2 3 5 8 13 34 2 3 5 8 21 34 2 3 5 13 21 34 2 3 8 13 21 34 2 5 8 13 21 34 3 5 8 13 21 34 Source 简单的DFS。。。 #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<limits.h> using namespace std; int num[15],a[15],k; int visit[15]; void dfs(int l,int s) { if(s==6) { for(int i=0;i<6;i++) printf(i==5?"%d\n":"%d ",num[i]); } for(int i=l;i<k;i++) { if(!visit[i]) { visit[i]=1; num[s]=a[i]; dfs(i,s+1); visit[i]=0; } } } int main() { while(cin>>k&&k) { for(int i=0;i<k;i++) cin>>a[i]; for(int i=0;i<=k-6;i++) { memset(visit,0,sizeof(visit)); visit[i]=1; num[0]=a[i]; dfs(i+1,1); } cout<<endl; } return 0; } |
周赛 POJ 2245 Lotto