北大ACM(POJ1012-Joseph)

 1 Memory: 220K        Time: 329MS
 2 Language: C++       Result: Accepted
 3 
 4 #include <iostream>
 5 using namespace std;
 6 bool calc(int k,int m)
 7 {
 8     int pos=0;
 9     int sum=2*k;
10     bool flag=true;
11     while(sum>k)
12     {
13         pos=(m+pos-1)%sum;
14         if(pos<k) flag=false;
15         sum--;
16     }
17     return flag;
18 }
19 int main()
20 {
21     int k;
22     int r[13];
23     for(k=1;k<14;k++)
24     {
25         int m=k+1;
26         while(true)
27         {
28             if(calc(k,m)) {
29                 r[k-1]=m;
30                 break;
31             }else if(calc(k,m+1)) {
32                 r[k-1]=m+1;
33                 break;
34             }
35             m+=k+1;
36         }
37     }
38     while(cin>>k && k>0)
39     {
40         cout<<r[k-1]<<endl;
41     }
42 }