46 lines
873 B
C++
46 lines
873 B
C++
#include <bits/stdc++.h>
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using namespace std;
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int main() {
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int n;
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cin >> n;
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set<long>hatvanyok;
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set<long>hasznalt;
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long a = 2;
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for (int i =0; i < 30; i++) {
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hatvanyok.insert(a);
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a = a * 2;
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//cout<<a<< " ";
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}
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//cout<< endl;
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// for (int x : hatvanyok) {
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// cout<<x<<" ";
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// }
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//cout<<endl;
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vector<int> szamok(n);
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for (int i = 0; i < n; i++) {
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cin >> szamok[i];
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}
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int out = 0;
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for (int i = 0; i < n; i++) {
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for (int j = i+1; j < n; j++) {
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if (!hasznalt.count(szamok[i] + szamok[j])) {
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if (hatvanyok.count(szamok[i] + szamok[j])) {
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out++;
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hasznalt.insert(szamok[i] + szamok[j]);
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}
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} else {
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out++;
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}
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}
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}
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cout<<out;
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} |