hdoj1592

Half of and a Half

 1 //大数问题
 2 #include<iostream>
 3 #include<stdio.h>
 4 #include<string.h>
 5 using namespace std;
 6 int N, len;
 7 int ans[10100];
 8 int main()
 9 {
10     while (scanf("%d", &N) != EOF) {
11     memset(ans, 0, sizeof(ans));
12     len = 0;
13     ans[0] = 1;
14     for (int i = 1; i <= N; ++i) {
15         for (int j = 0; j <= len; ++j)
16         ans[j] *= 2;
17         ans[0]++;
18         for (int j = 0; j <= len; ++j)
19         if (ans[j] > 9) {
20             ans[j + 1] += ans[j] / 10;
21             ans[j] %= 10;
22         }
23         if (ans[len + 1])
24         len++;
25     }
26     while (len >= 0) {
27         printf("%d", ans[len]);
28         len--;
29     }
30     printf("\n");
31     }
32 }