03a.c

   1 #include <stdio.h>
   2
   3 int main(void)
   4 {
   5         int bits[100] = {0};
   6         int i = 0, maxi = 0, c;
   7         while ((c = getchar()) != EOF) {
   8                 if (c == '0')
   9                         bits[i++] -= 1;
  10                 else if (c == '1')
  11                         bits[i++] += 1;
  12                 else if (c == '\n')
  13                         i = 0;
  14                 maxi = i > maxi ? i : maxi;
  15         }
  16
  17         int gamma = 0, epsilon = 0;
  18         for (int j = 0; j<maxi; j++) {
  19                 gamma *= 2;
  20                 epsilon *= 2;
  21                 if (bits[j] > 0)
  22                         gamma++;
  23                 else
  24                         epsilon++;
  25         }
  26         printf("%d\n", gamma*epsilon);
  27         return 0;
  28 }