TOJ1164: 最大公因子

 1 #include<iostream>
 2 #include<algorithm>
 3 using namespace std;
 4
 5 int fun(int m, int n)
 6 {
 7     int max_commondivisor;
 8     int m1 = max(m, n), n1 = min(m,n);
 9     int r = m1%n1;
10     while (1)
11     {
12         if (r == 0)
13         {
14             max_commondivisor = n1; break;
15         }
16         else
17         {
18             m1 = n1;
19             n1 = r;
20             r = m1%n1;
21         }
22     }
23     return max_commondivisor;
24 }
25
26 int main()
27 {
28     int m,n;
29     while (cin >> m>>n, m||n)
30     {
31         cout <<fun(m,n)<< endl;
32     }
33     return 0;
34 }

大数取余小数，小数取代大数，余数取代小数，直到余数取为0，最大公因子即为此时的小数。