Submission #891796

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Source Code Expand

#include <vector>
#include <iostream>

int main()
{
	std::vector<std::vector<int>> nakayosimap;
	int n;
	std::cin >> n;

	nakayosimap.resize(n);
	for (int i = 0; i < n; i++) {
		nakayosimap.at(i).assign(n, 0);
	}

	for (int i = 0; i < n; i++) {
		int suki;
		std::cin >> suki;
		nakayosimap.at(i).at(suki - 1) = 1;
	}

	int count = 0;
	for (int i = 0; i < n; i++) {
		for (int j = i; j < n; j++) {
			if (nakayosimap.at(i).at(j) == 1 && nakayosimap.at(j).at(i) == 1) {
				count++;
			}
		}
	}


	std::cout << count << std::endl;

}

Submission Info

Judge Result