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23 lines
533 B
C++

#define _CRT_SECURE_NO_WARNINGS
#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
#include <bits/stdc++.h>
using namespace std;
int main()
{
ios::sync_with_stdio(false);
int64_t n, k;
cin >> n >> k;
vector<int64_t> v(n);
unordered_map<int64_t, int64_t> m1, m2;
for (auto &x : v) cin >> x, m2[x]++;
int64_t ans = 0;
for (auto &x : v)
{
--m2[x];
if (x % k == 0)
ans += m1[x / k] * m2[x * k];
++m1[x];
}
cout << ans;
return 0;
}