package main

import (
    "fmt"
)

func abs(x int) int {
    if x < 0 {
        return -x
    }
    return x
}

func max(x, y int) int {
    if x > y {
        return x
    }
    return y
}

func min(x, y int) int {
    if x < y {
        return x
    }
    return y
}

func outOfBounds(i, j, n int) bool {
    return !(i >= 0 && i < n && j >= 0 && j < n)
}

func isCovered(i, j int, covered [][]bool) bool {
    if outOfBounds(i, j, len(covered)) {
        return true
    }
    return covered[i][j]
}

func generateMatrix(A int) [][]int {
    n := A
    matrix := make([][]int, n, n)
    for i := range matrix {
        matrix[i] = make([]int, n, n)
    }

    covered := make([][]bool, n, n)
    for i := range covered {
        covered[i] = make([]bool, n, n)
    }

    deltai := []int{0, 1, 0, -1}
    deltaj := []int{1, 0, -1, 0}

    x := 1
    i, j, k := 0, 0, 0
    ni, nj := 0, 0
    max := n*n + 2*n
    for y := 0; y < max; y++ {
        matrix[i][j] = x
        covered[i][j] = true
        ni = i + deltai[k]
        nj = j + deltaj[k]
        if isCovered(ni, nj, covered) {
            k = (k + 1) % 4
            x--
        } else {
            i, j = ni, nj
        }
        x++
    }

    return matrix
}

func main() {
    mat := generateMatrix(10)
    for i := range mat {
        for j := range mat[i] {
            fmt.Print(mat[i][j], " ")
        }
        fmt.Println()
    }
}