20 lines
332 B
C++
20 lines
332 B
C++
#include <unordered_set>
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#include <iostream>
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using namespace std;
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int main(){
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unordered_multiset<int> s;
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int n, m;
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cin >> n >> m;
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int tmp;
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for(int i = 0; i < n; i++){
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cin >> tmp;
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s.emplace(tmp);
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}
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int js = 0;
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for(auto it = s.begin(); it != s.end(); it++){
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js += s.count(*it - m);
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}
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cout << js << endl;
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return 0;
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}
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