Today Pari and Arya are playing a game called Remainders.
Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the value . There are n ancient numbers c1, c2, ..., cn and Pari has to tell Arya if Arya wants. Given k and the ancient values, tell us if Arya has a winning strategy independent of value of x or not. Formally, is it true that Arya can understand the value for any positive integer x?
Note, that means the remainder of x after dividing it by y.
The first line of the input contains two integers n and k (1 ≤ n, k ≤ 1 000 000) — the number of ancient integers and value k that is chosen by Pari.
The second line contains n integers c1, c2, ..., cn (1 ≤ ci ≤ 1 000 000).
Print "Yes" (without quotes) if Arya has a winning strategy independent of value of x, or "No" (without quotes) otherwise.
4 5
2 3 5 12
Yes
2 7
2 3
No
In the first sample, Arya can understand because 5 is one of the ancient numbers.
In the second sample, Arya can't be sure what is. For example 1 and 7 have the same remainders after dividing by 2 and 3, but they differ in remainders after dividing by 7.
题意:给你n个数,一个k;可以告诉你xmod ci的值;求x%k是否唯一;
思路:根据中国剩余定理,如果中国剩余定理有解x,另外一个解为x+lcm(c0,c1...cn);
所以lcm%k==0;
#include<bits/stdc++.h> using namespace std; #define ll __int64 #define mod 1000000007 #define pi (4*atan(1.0)) const int N=1e3+10,M=1e6+10,inf=1e9+10; ll gcd(ll a,ll b) { return b==0?a:gcd(b,a%b); } int main() { ll x,y,z,i,t; ll lcm=1; scanf("%lld%lld",&x,&y); for(i=0;i<x;i++) { scanf("%lld",&z); lcm=z*lcm/gcd(z,lcm); lcm%=y; } if(lcm==0) printf("Yes "); else printf("No "); return 0; }