Interview 150

Single Number

Problem
LC 136
File
interview150_LC136SingleNumber.java
Path
pkg5leetcode/interview150/interview150_LC136SingleNumber.java
Package
pkg5leetcode.interview150
Command
java pkg5leetcode/interview150/interview150_LC136SingleNumber.java
Approach
XOR all numbers; duplicates cancel to zero.
Complexity
Time O(n), Space O(1)

LeetCode solutions

There is no in-browser runner. This is the file from the curriculum, unchanged.

pkg5leetcode/interview150/interview150_LC136SingleNumber.java
1package pkg5leetcode.interview150;2 3/*4 * Single Number | LC 1365 * APPROACH: XOR all numbers; duplicates cancel to zero.6 * COMPLEXITY: Time O(n), Space O(1)7 */8public class interview150_LC136SingleNumber {9    static int singleNumber(int[] nums) {10        int x = 0;11        for (int n : nums) x ^= n;12        return x;13    }14 15    public static void main(String[] args) {16        check(singleNumber(new int[]{2, 2, 1}) == 1, "case1");17        check(singleNumber(new int[]{4, 1, 2, 1, 2}) == 4, "case2");18        System.out.println("all tests passed");19    }20 21    static void check(boolean cond, String name) {22        if (!cond) throw new AssertionError("FAILED: " + name);23        System.out.println("  PASS " + name);24    }25}