How many integers can you find
Time Limit:5000MS
Memory Limit:32768KB
64bit IO Format:%I64d & %I64u Submit Status Appoint description:
Description
Now you get a number N, and a M-integers set, you should find out how many integers which are small than N, that they can divided exactly by any integers in the set. For example, N=12, and M-integer set is {2,3}, so there is another set {2,3,4,6,8,9,10}, all the integers of the set can be divided exactly by 2 or 3. As a result, you just output the number 7.
Input
There are a lot of cases. For each case, the first line contains two integers N and M. The follow line contains the M integers, and all of them are different from each other. 0
Output
For each case, output the number.
Sample Input
12 2
2 3
Sample Output
7
题目大意：给出一个n和一个集合，m个数，问在1到n内 能被m中的数正除的有多少？
可以理解为在1到n内，是m中的数的倍数的数有多少？
在容斥原理中，用二进制数表示第i个数取没取，如果取了奇数个数，加上。 取了偶数个数，减去
#include
#include
#include
using namespace std ; #define LL long long LL a[12] ; LL n , m , k , i , j , cnt , num , ans ; LL gcd(LL x,LL y) { return x == 0 ? y : gcd(y%x,x) ; } int main() { while(scanf("%lld %lld", &n, &m) != EOF) { ans = 0 ; for(i = 0 ; i < m ; i++) { scanf("%lld", &a[i]) ; if( a[i] == 0 ) { i-- ; m-- ; } } cnt = 1 << m ; for(i = 1 ; i < cnt ; i++) { k = 1 ; num = 0 ; for(j = 0 ; j < m ; j++) { if( 1<