The 3n + 1 problem

http://poj.org/problem?id=1207

此题注意比较n,m的大小，还有最后的原样输出。

 1 #include<stdio.h>
 2 int main()
 3 {
 4     int n,m,i,j,max,t;
 5     while(~scanf("%d%d",&n,&m))
 6     {
 7         int n1 = n;
 8         int m1 = m;
 9         max = 0;
10         if(n > m)
11         {
12             t = n;
13             n = m;
14             m = t;
15         }
16         for (i = n; i <= m; i ++)
17         {
18             int cnt = 1;
19             j = i;
20             while(j!=1)
21             {
22                 if (j%2==0)
23                 {
24                     j /= 2;
25                 }
26                 else
27                 {
28                     j = 3*j+1;
29                 }
30                 cnt++;
31             }
32             if (cnt > max)
33                 max = cnt;
34         }
35         printf("%d %d %d\n",n1,m1,max);
36     }
37     return 0;
38 }
View Code

 

posted @ 2013-08-02 11:12  N_ll  阅读(139)  评论(0)  编辑  收藏  举报