diagonal-difference.js

"use strict";

const fs = require("fs");

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

let inputString = "";
let currentLine = 0;

process.stdin.on("data", function (inputStdin) {
  inputString += inputStdin;
});

process.stdin.on("end", function () {
  inputString = inputString.split("\n");

  main();
});

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

/*
 * Complete the 'diagonalDifference' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts 2D_INTEGER_ARRAY arr as parameter.
 */

/**
 * Calculate the absolute diagonal difference
 * @date 2022-03-26
 * @param {number[][]} grid
 * @returns {any}
 */
function diagonalDifference(grid) {
  let leftDiagonalSum = 0;
  let rightDiagonalSum = 0;

  const width = grid.length;

  grid.forEach((c, i) => {
    leftDiagonalSum += c[i];
    rightDiagonalSum += c[width - 1 - i];
  });

  return Math.abs(leftDiagonalSum - rightDiagonalSum);
}

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

  const n = parseInt(readLine().trim(), 10);

  let arr = Array(n);

  for (let i = 0; i < n; i++) {
    arr[i] = readLine()
      .replace(/\s+$/g, "")
      .split(" ")
      .map((arrTemp) => parseInt(arrTemp, 10));
  }

  const result = diagonalDifference(arr);

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

  ws.end();
}