Maximal Square LeetCode Solution

Here, We see Maximal Square problem Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc., with different approaches.

Maximal Square LeetCode Solution

Problem Statement ->

Given an m x n binary matrix filled with 0’s and 1’s, find the largest square containing only 1’s and return its area.

Example 1: (fig-1)
Input: matrix = [["1","0","1","0","0"],["1","0","1","1","1"],["1","1","1","1","1"],["1","0","0","1","0"]]
Output: 4

Example 2: (fig-2)
Input: matrix = [["0","1"],["1","0"]]
Output: 1

Example 3:
Input: matrix = [["0"]]
Output: 0

• C++ Solution
• Java Solution
• JavaScript Solution
• Python Solution

Maximal Square Leetcode Solution C++ ->

class Solution {
public:
    int maximalSquare(vector<vector<char>>& matrix) {
        if (matrix.empty()) {
            return 0;
        }
        int m = matrix.size(), n = matrix[0].size(), sz = 0;
        vector<vector<int>> dp(m, vector<int>(n, 0));
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                if (!i || !j || matrix[i][j] == '0') {
                    dp[i][j] = matrix[i][j] - '0';
                } else {
                    dp[i][j] = min(dp[i - 1][j - 1], min(dp[i - 1][j], dp[i][j - 1])) + 1;
                }
                sz = max(dp[i][j], sz);
            }
        }
        return sz * sz;
    }
};
Code language: C++ (cpp)

Maximal Square Leetcode Solution Java ->

class Solution {
    public int maximalSquare(char[][] matrix) {
        if (matrix == null || matrix.length == 0 || matrix[0].length == 0)
    return 0;
      
  int max = 0, n = matrix.length, m = matrix[0].length;
  int[][] dp = new int[n + 1][m + 1];
  
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      if (matrix[i - 1][j - 1] == '1') {
        dp[i][j] = Math.min(dp[i - 1][j - 1], Math.min(dp[i - 1][j], dp[i][j - 1])) + 1;
        max = Math.max(max, dp[i][j]);
      }
    }
  }
  return max * max;
    }
}
Code language: Java (java)

Maximal Square Leetcode Solution JavaScript ->

var maximalSquare = function(matrix) {
    let max = 0
  for (let i = 0; i < matrix.length; i++) {
    for (let j = 0; j < matrix[0].length; j++) {
      if (matrix[i][j] === "0") continue
      if(i > 0 && j > 0)
        matrix[i][j] = Math.min(matrix[i - 1][j], matrix[i][j - 1], matrix[i - 1][j - 1]) + 1
      max = Math.max(matrix[i][j], max)
    }
  }
  return max ** 2
};
Code language: JavaScript (javascript)

Maximal Square Leetcode Solution Python ->

class Solution(object):
    def maximalSquare(self, matrix):
        if matrix is None or len(matrix) < 1:
            return 0
        
        rows = len(matrix)
        cols = len(matrix[0])
        
        dp = [[0]*(cols+1) for _ in range(rows+1)]
        max_side = 0
        
        for r in range(rows):
            for c in range(cols):
                if matrix[r][c] == '1':
                    dp[r+1][c+1] = min(dp[r][c], dp[r+1][c], dp[r][c+1]) + 1 # Be careful of the indexing since dp grid has additional row and column
                    max_side = max(max_side, dp[r+1][c+1])
                
        return max_side * max_side
Code language: Python (python)