UVALive 6661 Equal Sum Sets

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <string>
 7 #include <vector>
 8 #include <map>
 9 #include <set>
10 #include <time.h>
11 #include <queue>
12 #include <stack>
13 #include <cctype>
14 #include <utility>
15 #include <numeric>
16 #include <cstdlib>
17 #include <functional>
18 #include <iomanip>
19 #include <sstream>
20 using namespace std;
21 int n,k,s;
22 int ans;
23 void gao(int now,int deep,int sum)
24 {
25   if(deep==k&&sum==s) {ans++;return ;}
26   if(deep>k||sum>s) return ;
27   else
28     for(int i=now+1;i<=n;i++)
29       gao(i,deep+1,sum+i);
30   return ;
31 }
32 int main()
33 {
34 
35   while(scanf("%d%d%d",&n,&k,&s)!=EOF)
36   {
37     if(n+k+s==0) break;
38     ans=0;
39     for(int i=1;i<=n;i++)
40       gao(i,1,i);
41     printf("%d\n",ans);
42   }
43   return 0;
44 }

View Code