LeetCode: Transpose Matrix

Transpose Matrix

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• Tag: #array

Given a matrix A, return the transpose of A.

The transpose of a matrix is the matrix flipped over it’s main diagonal, switching the row and column indices of the matrix.

Example 1:

Input: [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]

Example 2:

Input: [[1,2,3],[4,5,6]]
Output: [[1,4],[2,5],[3,6]]

Note:

1. 1 <= A.length <= 1000
2. 1 <= A[0].length <= 1000

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

• Solution:

// https://code.dennyzhang.com/transpose-matrix
// Basic Ideas:
// Complexity: Time O(n*m), Space O(1)
func transpose(A [][]int) [][]int {
    if len(A) == 0 { return [][]int{} }
    row_count, col_count := len(A), len(A[0])
    res := make([][]int, col_count)
    for i, _ := range res { res[i] = make([]int, row_count) }

    for j:= 0; j<col_count; j++ {
        for i:=0; i<row_count; i++ {
            res[j][i] = A[i][j]
        }
    }
    return res
}