32 lines
799 B
Java
32 lines
799 B
Java
// Author: Rodney Shaghoulian
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// Github: github.com/RodneyShag
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// HackerRank: hackerrank.com/RodneyShag
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import java.util.Scanner;
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import java.util.HashSet;
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public class Solution {
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public static void main(String[] args) {
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/* Read some input */
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Scanner scan = new Scanner(System.in);
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int n = scan .nextInt();
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/* Count pairs */
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HashSet<Integer> set = new HashSet<>();
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int pairs = 0;
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for (int i = 0; i < n; i++) {
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int cost = scan.nextInt();
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if (set.contains(cost)) {
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set.remove(cost);
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pairs++;
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} else {
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set.add(cost);
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}
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}
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/* Print output */
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scan.close();
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System.out.println(pairs);
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}
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}
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