【ZOJ】2836 Number Puzzle

题意：同【HDU】1796 How many integers can you find。

 1 #include<cstdio>

 2 #include<algorithm>

 3 typedef long long LL;

 4 #define MAXN 110

 5 using namespace std;

 6 int m;

 7 LL n, ans;

 8 int a[MAXN];

 9 LL GCD(LL x, LL y) {

10     return y ? GCD(y, x % y) : x;

11 }

12 LL LCM(LL x, LL y) {

13     return x / GCD(x, y) * y;

14 }

15 LL Get(int x, int &cnt) {

16     int i;

17     LL res = 1;

18     for (i = cnt = 0; i < m; i++) {

19         if (x & (1 << i)) {

20             cnt++;

21             res = LCM(res, a[i]);

22         }

23     }

24     return res;

25 }

26 int main() {

27     int i, k;

28     LL tmp;

29     while (~scanf("%d%lld", &m, &n)) {

30         for (ans = i = 0; i < m; i++)

31             scanf("%d", &a[i]);

32         for (i = 1; i < (1 << m); i++) {

33             tmp = Get(i, k);

34             if (k & 1)

35                 ans += n / tmp;

36             else

37                 ans -= n / tmp;

38         }

39         printf("%lld\n", ans);

40     }

41     return 0;

42 }