David Lowes

The lonely integer

HackerRank > Cracking the Coding Interview > Bit Manipulation: Lonely Integer

Consider an array of integers, , where all but one of the integers occur in pairs. In other words, every element in occurs exactly twice except for one unique element.
Given , find and print the unique element.

Input Format
- The first line contains a single integer, , denoting the number of integers in the array.
- The second line contains space-separated integers describing the respective values in.

Solution

process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();
});

function readLine() {
    return input_stdin_array[input_currentline++];
}


function main() {
    var n = parseInt(readLine());
    a = readLine().split(' ');
    a = a.map(Number);

/////////////// start code here ////////////////////

    var arr = a; //readability
    for (let i=0; i'<'arr.length; i++) {
        arr.sort(); // sort array so you can compare left and right values, shown below
        if(arr[i] !== arr[i +1] && arr[i] !== arr[i -1]) {
            console.log(arr[i]);
        }
    }
}