AlgoLounge

Longest Increasing Path in a Matrix

hard

Given an m x n integers matrix, return the length of the longest increasing path.

From each cell, you can either move in four directions: left, right, up, or down. You may not move diagonally or move outside the boundary (i.e., wrap-around is not allowed).

Examples

Example 1

Input:  matrix = [

[9,9,4], [6,6,8], [2,1,1] ] Output: 4 The longest increasing path is [1, 2, 6, 9].

Example 2

Input:  matrix = [

[3,4,5], [3,2,6], [2,2,1] ] Output: 4 The longest increasing path is [3, 4, 5, 6]. Moving diagonally is not allowed.

Example 3

Input:  matrix = [[1]]
Output: 1

Constraints

  • m == matrix.length
  • n == matrix[i].length
  • 1 <= m, n <= 200
  • 0 <= matrix[i][j] <= 2^31 - 1
TypeScript
Loading editor…
List of test cases (10)
Case 1
matrix = [[9,9,4],[6,6,8],[2,1,1]]
Case 2
matrix = [[3,4,5],[3,2,6],[2,2,1]]
Case 3
matrix = [[1]]
Case 4
matrix = [[1,2,3,4,5]]
Case 5
matrix = [[1],[2],[3],[4],[5]]
Case 6
matrix = [[5,4,3],[2,1,0]]
Case 7
matrix = [[1,2],[4,3]]
Case 8
matrix = [[7,8,9],[9,7,6],[7,2,3]]
Case 9
matrix = [[0,1,2,3,4,5,6,7,8,9]]
Case 10
matrix = [[1,1,1],[1,1,1],[1,1,1]]