Question

How to transpose a matrix (swap rows and columns) in Go

Answer 1

package main

import (
    "fmt"
)

func Transpose(matrix [][]int) [][]int {
    rows := len(matrix)
    cols := len(matrix[0])

    // allocate transposed matrix
    result := make([][]int, cols)
    for i := range result {
        result[i] = make([]int, rows)
    }

    // fill transposed values
    for i := 0; i < rows; i++ {
        for j := 0; j < cols; j++ {
            result[j][i] = matrix[i][j]
        }
    }

    return result
}

func Print(matrix [][]int) {
    for _, row := range matrix {
        fmt.Println(row)
    }
}

func main() {
    matrix := [][]int{
        {1, 2, 3},
        {4, 5, 6},
        {7, 8, 9},
    }

    t := Transpose(matrix)
    Print(t)
}



/*
run:

[1 4 7]
[2 5 8]
[3 6 9]

*/

 

70+ SQL courses for beginners and professionals