Codeforces 791A Bear and Big Brother(暴力枚举,模拟)

In the first sample, Limak weighs 4 and Bob weighs 7 initially. After one year their weights are 4·3 = 12 and 7·2 = 14 respectively (one weight is tripled while the other one is doubled). Limak isn't larger than Bob yet. After the second year weights are 36 and 28, so the first weight is greater than the second one. Limak became larger than Bob after two years so you should print 2.

In the second sample, Limak's and Bob's weights in next years are: 12 and 18, then 36 and 36, and finally 108 and 72 (after three years). The answer is 3. Remember that Limak wants to be larger than Bob and he won't be satisfied with equal weights.

In the third sample, Limak becomes larger than Bob after the first year. Their weights will be 3 and 2 then.

分析：给你两个数字a和b; a每次乘3,b每次乘2，问你什么时候a第一次大于b！

题目链接：http://codeforces.com/contest/791/problem/A

下面给出AC代码：

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 int main()
 4 {
 5     int a,b,i;
 6     int c,d;
 7     while(scanf("%d%d",&a,&b)!=EOF)
 8     {
 9         int ans=0;
10         if(a-b>0)
11             printf("0\n");
12             else if(a-b==0)
13                 printf("1\n");
14         while(a-b<0)
15         {
16             ans++;
17             a*=3;
18             b*=2;
19             if(a-b>0)
20             {
21                 printf("%d\n",ans);
22                 break;
23             }
24             else if(a-b==0)
25             {
26                 printf("%d\n",ans+1);
27                 break;
28             }
29         }
30     }
31     return 0;
32 }