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20 lines
354 B
C++
20 lines
354 B
C++
#include <bits/stdc++.h>
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using namespace std;
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int main() {
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long long n, c, ans = 0;
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int a[200005];
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map<int, int> b;
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cin >> n >> c;
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for (int i = 1; i <= n; i++) {
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cin >> a[i];
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b[a[i]]++;
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}
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for (int i = 1; i <= n; i++) {
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ans += b[a[i] + c];
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}
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cout << ans << endl;
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return 0;
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}
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