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2133. Check if Every Row and Column Contains All Numbers

Description

An n x n matrix is valid if every row and every column contains all the integers from 1 to n (inclusive).

Given an n x n integer matrix matrix, return true if the matrix is valid. Otherwise, return false.

 

Example 1:

Input: matrix = [[1,2,3],[3,1,2],[2,3,1]]
Output: true
Explanation: In this case, n = 3, and every row and column contains the numbers 1, 2, and 3.
Hence, we return true.

Example 2:

Input: matrix = [[1,1,1],[1,2,3],[1,2,3]]
Output: false
Explanation: In this case, n = 3, but the first row and the first column do not contain the numbers 2 or 3.
Hence, we return false.

 

Constraints:

  • n == matrix.length == matrix[i].length
  • 1 <= n <= 100
  • 1 <= matrix[i][j] <= n

Solutions

  • class Solution {
        public boolean checkValid(int[][] matrix) {
            int n = matrix.length;
            for (int i = 0; i < n; ++i) {
                boolean[] seen = new boolean[n];
                for (int j = 0; j < n; ++j) {
                    int v = matrix[i][j] - 1;
                    if (seen[v]) {
                        return false;
                    }
                    seen[v] = true;
                }
            }
            for (int j = 0; j < n; ++j) {
                boolean[] seen = new boolean[n];
                for (int i = 0; i < n; ++i) {
                    int v = matrix[i][j] - 1;
                    if (seen[v]) {
                        return false;
                    }
                    seen[v] = true;
                }
            }
            return true;
        }
    }
    
  • class Solution {
    public:
        bool checkValid(vector<vector<int>>& matrix) {
            int n = matrix.size();
            for (int i = 0; i < n; ++i) {
                vector<bool> seen(n);
                for (int j = 0; j < n; ++j) {
                    int v = matrix[i][j] - 1;
                    if (seen[v]) return false;
                    seen[v] = true;
                }
            }
            for (int j = 0; j < n; ++j) {
                vector<bool> seen(n);
                for (int i = 0; i < n; ++i) {
                    int v = matrix[i][j] - 1;
                    if (seen[v]) return false;
                    seen[v] = true;
                }
            }
            return true;
        }
    };
    
  • class Solution:
        def checkValid(self, matrix: List[List[int]]) -> bool:
            n = len(matrix)
            for i in range(n):
                seen = [False] * n
                for j in range(n):
                    v = matrix[i][j] - 1
                    if seen[v]:
                        return False
                    seen[v] = True
            for j in range(n):
                seen = [False] * n
                for i in range(n):
                    v = matrix[i][j] - 1
                    if seen[v]:
                        return False
                    seen[v] = True
            return True
    
    
  • func checkValid(matrix [][]int) bool {
    	n := len(matrix)
    	for i := 0; i < n; i++ {
    		seen := make([]bool, n)
    		for j := 0; j < n; j++ {
    			v := matrix[i][j] - 1
    			if seen[v] {
    				return false
    			}
    			seen[v] = true
    		}
    	}
    	for j := 0; j < n; j++ {
    		seen := make([]bool, n)
    		for i := 0; i < n; i++ {
    			v := matrix[i][j] - 1
    			if seen[v] {
    				return false
    			}
    			seen[v] = true
    		}
    	}
    	return true
    }
    
  • function checkValid(matrix: number[][]): boolean {
        const n = matrix.length;
        let rows = Array.from({ length: n }, () => new Array(n).fill(false));
        let cols = Array.from({ length: n }, () => new Array(n).fill(false));
        for (let i = 0; i < n; i++) {
            for (let j = 0; j < n; j++) {
                let cur = matrix[i][j];
                if (rows[i][cur] || cols[j][cur]) return false;
                rows[i][cur] = true;
                cols[j][cur] = true;
            }
        }
        return true;
    }
    
    

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