二进制整数转十进制 - 位运算的应用

 1 #include "stdio.h"
 2 #include "string.h"
 3 const int maxn = 100000;
 4 int main(int argc, char const *argv[])
 5 {
 6     char indata[maxn];
 7         memset(indata,0,sizeof(indata));
 8     while(scanf("%s",indata)!=EOF)
 9     {
10         int n = strlen(indata);
11         unsigned long long sum = 0;
12         for(int i=n-1;i>=0;i--)
13         {
14             unsigned long long k = indata[i]-‘0‘;
15             sum += (k<<(n-i-1));
16         }
17         printf("%llu\n",sum );
18     }
19     return 0;
20 }