hihocoder 扩展二进制数

 1 #include <iostream>
 2 #include <cstdio>
 3 using namespace std;
 4 
 5 int dfs(int x)
 6 {
 7     if (x <= 1)
 8         return 1;
 9     if (x & 1)
10         return dfs((x - 1) >> 1);
11     return dfs(x >> 1) + dfs((x - 2) >> 1);
12 }
13 
14 int main()
15 {
16     int n;
17     cin >> n;
18     cout << dfs(n) << endl;
19     return 0;
20 }