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

Solution 1

Python Code
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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

Java Code
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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;
    }
}

C++ Code
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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;
    }
};

Go Code
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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
}

TypeScript Code
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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;
}