【HDOJ】2721 Persistent Bits

题目有点长，但是题意说的很清楚。位操作。

 #include <stdio.h>

 int nums[];

 int main() {
     int a, b, c, s;
     int i, j, k, n, tmp, mask;

     while (scanf("%d", &a)!=EOF && a) {
         scanf("%d%d%d", &b, &c, &s);
         n = mask = ;
         nums[n++] = tmp = s;
         a = a%c;
         b = b%c;
         for (j=; j<; ++j) {
             tmp = (a*tmp + b) % c;
             if (tmp == s)
                 break;
             nums[n++] = tmp;
             k = tmp ^ s;
             mask |= k;
             if (mask == 0xffff)
                 break;
         }
         j = 0x8000;
         for (i=; i<; ++i) {
             tmp = (j>>i);
             k = tmp & s;
             tmp &= mask;
             if (tmp)
                 printf("?");
             else {
                 if (k)
                     printf("");
                 else
                     printf("");
             }
         }
         printf("\n");
     }

     return ;
 }