Welcome to Subscribe On Youtube
Formatted question description: https://leetcode.ca/all/2128.html
2128. Remove All Ones With Row and Column Flips (Medium)
You are given an m x n binary matrix grid.
In one operation, you can choose any row or column and flip each value in that row or column (i.e., changing all 0's to 1's, and all 1's to 0's).
Return true if it is possible to remove all 1's from grid using any number of operations or false otherwise.
Example 1:

Input: grid = [[0,1,0],[1,0,1],[0,1,0]] Output: true Explanation: One possible way to remove all 1's from grid is to: - Flip the middle row - Flip the middle column
Example 2:

Input: grid = [[1,1,0],[0,0,0],[0,0,0]] Output: false Explanation: It is impossible to remove all 1's from grid.
Example 3:

Input: grid = [[0]] Output: true Explanation: There are no 1's in grid.
Constraints:
m == grid.lengthn == grid[i].length1 <= m, n <= 300grid[i][j]is either0or1.
Companies:
Google
Related Topics:
Array, Math, Bit Manipulation, Matrix
Similar Questions:
- Score After Flipping Matrix (Medium)
- Minimum Number of Flips to Convert Binary Matrix to Zero Matrix (Hard)
- Minimum Operations to Remove Adjacent Ones in Matrix (Hard)
Solution
-
class Solution { public boolean removeOnes(int[][] grid) { Set<String> s = new HashSet<>(); int n = grid[0].length; for (var row : grid) { var cs = new char[n]; for (int i = 0; i < n; ++i) { cs[i] = (char) (row[0] ^ row[i]); } s.add(String.valueOf(cs)); } return s.size() == 1; } } -
class Solution { public: bool removeOnes(vector<vector<int>>& grid) { unordered_set<string> s; for (auto& row : grid) { string t; for (int x : row) { t.push_back('0' + (row[0] == 0 ? x : x ^ 1)); } s.insert(t); } return s.size() == 1; } }; -
class Solution: def removeOnes(self, grid: List[List[int]]) -> bool: s = set() for row in grid: t = tuple(row) if row[0] == grid[0][0] else tuple(x ^ 1 for x in row) s.add(t) return len(s) == 1 -
func removeOnes(grid [][]int) bool { s := map[string]bool{} for _, row := range grid { t := []byte{} for _, x := range row { if row[0] == 1 { x ^= 1 } t = append(t, byte(x)+'0') } s[string(t)] = true } return len(s) == 1 } -
function removeOnes(grid: number[][]): boolean { const s = new Set<string>(); for (const row of grid) { if (row[0] === 1) { for (let i = 0; i < row.length; i++) { row[i] ^= 1; } } const t = row.join(''); s.add(t); } return s.size === 1; }