链接:https://codeforces.ml/contest/1305/problem/C
To become the king of Codeforces, Kuroni has to solve the following problem.
He is given nn numbers a1,a2,…,ana1,a2,…,an. Help Kuroni to calculate ∏1≤i<j≤n|ai−aj|∏1≤i<j≤n|ai−aj|. As result can be very big, output it modulo mm.
If you are not familiar with short notation, ∏1≤i<j≤n|ai−aj|∏1≤i<j≤n|ai−aj| is equal to |a1−a2|⋅|a1−a3|⋅|a1−a2|⋅|a1−a3|⋅ …… ⋅|a1−an|⋅|a2−a3|⋅|a2−a4|⋅⋅|a1−an|⋅|a2−a3|⋅|a2−a4|⋅ …… ⋅|a2−an|⋅⋅|a2−an|⋅ …… ⋅|an−1−an|⋅|an−1−an|. In other words, this is the product of |ai−aj||ai−aj| for all 1≤i<j≤n1≤i<j≤n.
Input
The first line contains two integers nn, mm (2≤n≤2⋅1052≤n≤2⋅105, 1≤m≤10001≤m≤1000) — number of numbers and modulo.
The second line contains nn integers a1,a2,…,ana1,a2,…,an (0≤ai≤1090≤ai≤109).
Output
Output the single number — ∏1≤i<j≤n|ai−aj|modm∏1≤i<j≤n|ai−aj|modm.
Examples
input
Copy
2 10 8 5
output
Copy
3
input
Copy
3 12 1 4 5
output
Copy
0
input
Copy
3 7 1 4 9
output
Copy
1
Note
In the first sample, |8−5|=3≡3mod10|8−5|=3≡3mod10.
In the second sample, |1−4|⋅|1−5|⋅|4−5|=3⋅4⋅1=12≡0mod12|1−4|⋅|1−5|⋅|4−5|=3⋅4⋅1=12≡0mod12.
In the third sample, |1−4|⋅|1−9|⋅|4−9|=3⋅8⋅5=120≡1mod7|1−4|⋅|1−9|⋅|4−9|=3⋅8⋅5=120≡1mod7.
代码:
#include<bits/stdc++.h>
using namespace std;
long long n,m,t,s1,s2,s;
long long a[200001];
int main()
{
cin>>n>>m;
for(int i=1;i<=n;i++)
{
cin>>a[i];
}
if(n<=m)
{
s=1;
for(int i=1;i<=n;i++)
{
for(int j=i+1;j<=n;j++)
{
s*=abs(a[i]-a[j])%m;
s%=m;
}
}
cout<<s<<endl;
}
else
cout<<0<<endl;
}