34 lines
895 B
Java
34 lines
895 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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// O(n) runtime. O(1) space. Uses XOR. Keep in mind:
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// 1) x ^ x = 0
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// 2) x ^ 0 = x
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// 3) XOR is commutative and associative
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public class Solution {
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public static void main(String[] args) {
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/* Save input */
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Scanner scan = new Scanner(System.in);
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int n = scan.nextInt();
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int [] array = new int[n];
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for(int i = 0; i < n; i++){
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array[i] = scan.nextInt();
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}
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scan.close();
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System.out.println(lonelyInteger(array));
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}
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/* XORs all numbers in array together */
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public static int lonelyInteger(int [] array) {
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int val = 0;
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for (int num : array) {
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val = val ^ num; // ^ is XOR operator
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}
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return val;
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}
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}
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