Array Manipulation Hacker Rank

arrayManipulation.js

'use strict';

const fs = require('fs');

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', inputStdin => {
    inputString += inputStdin;
});

process.stdin.on('end', _ => {
    inputString = inputString.replace(/\s*$/, '')
        .split('\n')
        .map(str => str.replace(/\s*$/, ''));

    main();
});

function readLine() {
    return inputString[currentLine++];
}

// Complete the arrayManipulation function below.
function arrayManipulation(n, queries) {
    // problem is known as prefix sum algo.
    const arr = new Array(n + 2).fill(0), qn = queries.length;
    let sum = 0, maxValue = 0;

    for (let i = 0; i < qn; i++) {
        const [min, max, sum] = queries[i];
        arr[min] += sum;
        maxValue = maxValue < sum ? sum : maxValue
        if (max <= n) {
            arr[max + 1] -= sum;
        }

    }
    for (let k = 0; k < n; k++) {
        sum += arr[k];
        if (maxValue < sum) {
            maxValue = sum;
        }
    }
    return maxValue;

}

function main() {
    const ws = fs.createWriteStream(process.env.OUTPUT_PATH);

    const nm = readLine().split(' ');

    const n = parseInt(nm[0], 10);

    const m = parseInt(nm[1], 10);

    let queries = Array(m);

    for (let i = 0; i < m; i++) {
        queries[i] = readLine().split(' ').map(queriesTemp => parseInt(queriesTemp, 10));
    }

    let result = arrayManipulation(n, queries);

    ws.write(result + "\n");

    ws.end();
}