【HDOJ】2721 Persistent Bits

题目有点长，但是题意说的很清楚。位操作。
 1 #include <stdio.h>
 2 
 3 int nums[65540];
 4 
 5 int main() {
 6     int a, b, c, s;
 7     int i, j, k, n, tmp, mask;
 8 
 9     while (scanf("%d", &a)!=EOF && a) {
10         scanf("%d%d%d", &b, &c, &s);
11         n = mask = 0;
12         nums[n++] = tmp = s;
13         a = a%c;
14         b = b%c;
15         for (j=0; j<65537; ++j) {
16             tmp = (a*tmp + b) % c;
17             if (tmp == s)
18                 break;
19             nums[n++] = tmp;
20             k = tmp ^ s;
21             mask |= k;
22             if (mask == 0xffff)
23                 break;
24         }
25         j = 0x8000;
26         for (i=0; i<16; ++i) {
27             tmp = (j>>i);
28             k = tmp & s;
29             tmp &= mask;
30             if (tmp)
31                 printf("?");
32             else {
33                 if (k)
34                     printf("1");
35                 else
36                     printf("0");
37             }
38         }
39         printf("
");
40     }
41 
42     return 0;
43 }