Find the difference between the sum of diagonals in a 2D matrix using JavaScript

Question

Find the difference between the sum of diagonals in a 2D matrix using JavaScript

I'm currently practicing on hackerrank and came across a challenge involving a two-dimensional matrix. Unfortunately, I encountered an error in my code implementation.

11 2 4
4 5 6
10 8 -12

The task at hand is to calculate the sum along the primary diagonal: 11 + 5 - 12 = 4, then the secondary diagonal: 4 + 5 + 10 = 19, finally resulting in 19 - 4 = 15.

function diagonalDifference(arr) {
     var sumRight = 0;
     var sumLeft = 0;
     var array = new Array();
     for(var i = 0; i < arr.length ; i++ ){
          for(var j = 0; j < arr[i].length; j++){
               array.push(arr[i][j]);
          }
     }
     for (var i = 0 ; i < array.length; i = i + 4){
          sumRight += array[i];
     }
     for (var j = 2 ; j < array.length - 1 ; j = j + 2 ){
          sumLeft += array[j];
     }
     return sumLeft - sumRight;
}

javascript

Answer 1

Answer №1

give this a shot

function calculateDiagonalSums(matrix) {

    let primarySum = 0, secondarySum = 0;
    for (let row = 0; row < matrix.length; row++) {
        primarySum += matrix[row][row];
        secondarySum += matrix[row][matrix.length - row - 1];
    }
    console.log(primarySum + ' ' + secondarySum);
    console.log(primarySum - secondarySum);
}

calculateDiagonalSums([[11,2,4],[4,5,6],[10,8,-12]]);

Answer 2

give this a shot

function calculateDiagonalSums(matrix) {

    let primarySum = 0, secondarySum = 0;
    for (let row = 0; row < matrix.length; row++) {
        primarySum += matrix[row][row];
        secondarySum += matrix[row][matrix.length - row - 1];
    }
    console.log(primarySum + ' ' + secondarySum);
    console.log(primarySum - secondarySum);
}

calculateDiagonalSums([[11,2,4],[4,5,6],[10,8,-12]]);

Answer 3

Answer №2

It appears that your current approach may not be leading in the right direction. A more effective solution involves calculating the sum of elements from the top-left to bottom-right (referred to as sumRigth). Subsequently, calculate the sum of elements from the top-right to bottom-left (stored as sumLeft). This assumes that the arrays consist of numbers and are of equal size.

function findDiagonalDifference(matrix) {
     let sumRigth = 0, sumLeft = 0, count = 0;
     for (let i = 0 ; i < matrix.length; i++){
          sumRigth += matrix[i][count++];
     }
     count = matrix.length-1;
     for (let i = 0; i < matrix.length; i++){
          sumLeft += matrix[i][count--];
     }
     return sumLeft - sumRigth;
}

let arr = [
     [11, 2, 4],
     [4, 5, 6],
     [10, 8, -12]
];
console.log(findDiagonalDifference(arr));

Answer 4

It appears that your current approach may not be leading in the right direction. A more effective solution involves calculating the sum of elements from the top-left to bottom-right (referred to as sumRigth). Subsequently, calculate the sum of elements from the top-right to bottom-left (stored as sumLeft). This assumes that the arrays consist of numbers and are of equal size.

function findDiagonalDifference(matrix) {
     let sumRigth = 0, sumLeft = 0, count = 0;
     for (let i = 0 ; i < matrix.length; i++){
          sumRigth += matrix[i][count++];
     }
     count = matrix.length-1;
     for (let i = 0; i < matrix.length; i++){
          sumLeft += matrix[i][count--];
     }
     return sumLeft - sumRigth;
}

let arr = [
     [11, 2, 4],
     [4, 5, 6],
     [10, 8, -12]
];
console.log(findDiagonalDifference(arr));

Answer 5

Answer №3

By utilizing a single loop, it is possible to obtain two values directly to use for summation.

function calculateSum(matrix) {
    let total = 0;

    for (let i = 0, length = matrix.length; i < length; i++)
        total += matrix[i][length - i - 1] - matrix[i][i];

    return total;
}

console.log(calculateSum([[11, 2, 4], [4, 5, 6], [10, 8, -12]]));

Answer 6

By utilizing a single loop, it is possible to obtain two values directly to use for summation.

function calculateSum(matrix) {
    let total = 0;

    for (let i = 0, length = matrix.length; i < length; i++)
        total += matrix[i][length - i - 1] - matrix[i][i];

    return total;
}

console.log(calculateSum([[11, 2, 4], [4, 5, 6], [10, 8, -12]]));

Find the difference between the sum of diagonals in a 2D matrix using JavaScript

Answer №1

Answer №2

Answer №3

Similar questions

Tips for utilizing [(ngModel)] with an object that is empty, null, or undefined in Angular 4

Automated resizing for various monitor dimensions in HTML

Sharing methods between controllers in AngularJS

Can you explain the significance of network activity groupings within the Firebug Net tab?

Is there a way to retrieve the hand-drawn lines at no cost in the form of a list, with each line represented as a collection of coordinates

What is an example scenario where Async Storage can be tested using Jest-expo?

Issues with resetting AngularJS form---"The AngularJS form

Efficient communication in Angular: Sharing data among controllers and components

What is the method for applying multiple criteria to filter an array in Vuejs?

Tips for dynamically loading JSON data in Pug and JavaScript by implementing scroll functionality

What is the best way to position a container div over another container using Bootstrap or CSS?

Unexpected outcome when returning a map

Having trouble loading CSS in an express view with a router

Struggling with adding documents into mongoDB with the help of mongoose and node.js

Step-by-step guide on dynamically adding "Input Tags" to the DOM at runtime using Selenium's JavascriptExecutor

Putting Text Inside a Video Player in HTML

What is the correct RegEx pattern I should use to properly match the provided test case without including the ending period?

Installing a package from a private repository using a different package name with npm

What is the best way to pass a selected item from a dropdown menu as an argument when calling a function from

Place an image at the top of the canvas at a specific location