Spiral Matrix

[jsartisan]

Info

difficulty: medium
title: Spiral Matrix
type: question
template: typescript
tags: javascript, blind75, matrix

Question

Given an m x n matrix, return all elements in spiral order (clockwise from outside to inside).

Rules:

• Start from top-left corner
• Move in clockwise direction
• Visit each element exactly once
• Return elements in order visited

Constraints:

• 1 ≤ matrix.length, matrix[i].length ≤ 10
• -100 ≤ matrix[i][j] ≤ 100

Examples:

// Example 1: 2x2 matrix
console.log(spiralOrder([[1,2],[3,4]]));
// Output: [1,2,4,3]

// Example 2: 3x3 matrix
console.log(spiralOrder([[1,2,3],[4,5,6],[7,8,9]]));
// Output: [1,2,3,6,9,8,7,4,5]

// Example 3: 3x4 matrix
console.log(spiralOrder([[1,2,3,4],[5,6,7,8],[9,10,11,12]]));
// Output: [1,2,3,4,8,12,11,10,9,5,6,7]

Template

index.ts

export function spiralOrder(matrix: number[][]): number[] {

}

index.test.ts

import { spiralOrder } from './index';

describe('spiralOrder', () => {
  test('Example 1: 2x2 matrix', () => {
    expect(spiralOrder([[1,2],[3,4]])).toEqual([1,2,4,3]);
  });

  test('Example 2: 3x3 matrix', () => {
    expect(spiralOrder([[1,2,3],[4,5,6],[7,8,9]]))
      .toEqual([1,2,3,6,9,8,7,4,5]);
  });

  test('Example 3: 3x4 matrix', () => {
    expect(spiralOrder([[1,2,3,4],[5,6,7,8],[9,10,11,12]]))
      .toEqual([1,2,3,4,8,12,11,10,9,5,6,7]);
  });

  test('1x1 matrix', () => {
    expect(spiralOrder([[7]])).toEqual([7]);
  });

  test('1xn matrix', () => {
    expect(spiralOrder([[1,2,3]])).toEqual([1,2,3]);
  });

  test('nx1 matrix', () => {
    expect(spiralOrder([[1],[2],[3]])).toEqual([1,2,3]);
  });

  test('4x4 matrix', () => {
    expect(spiralOrder([
      [1,2,3,4],
      [5,6,7,8],
      [9,10,11,12],
      [13,14,15,16]
    ])).toEqual([1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10]);
  });

  test('Matrix with negative numbers', () => {
    expect(spiralOrder([[-1,-2],[-3,-4]])).toEqual([-1,-2,-4,-3]);
  });

  test('2x3 matrix', () => {
    expect(spiralOrder([[1,2,3],[4,5,6]])).toEqual([1,2,3,6,5,4]);
  });

  test('3x2 matrix', () => {
    expect(spiralOrder([[1,2],[3,4],[5,6]])).toEqual([1,2,4,6,5,3]);
  });
});

[github-actions[bot]]

324 - Pull Request updated.