Go Spiral Matrix

Base spiral matrix implementation.

Setting up the test

Set up spiral_matrix_test.go with the following file to test inserts, retrievals and validations:

package sm

import (
    "fmt"
    "testing"
)

func TestMatrix(t *testing.T) {
    for _, tt := range testCases {
        res := genSpiralMatrix(tt.input)

        fmt.Println(res)

        for i, v := range res {
            for j := range v {
                if res[i][j] != tt.expected[i][j] {
                    t.Errorf("FAIL: Expected %+v but got %+v", tt.expected, res)
                    return
                }
            }
        }

        t.Logf("PASS: Expected %+v and got %+v", tt.expected, res)
    }
}
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Spiral Matrix Implementation

package caps

func genSpiralMatrix(s int) [][]int {
    m := make([][]int, s)

    for x := 0; x < s; x++ {
        m[x] = make([]int, s)
        for y := 0; y < s; y++ {
            m[x][y] = 0
        }
    }

    count := 1
    startCol := 0
    endCol := s - 1
    startRow := 0
    endRow := s - 1

    for startCol <= endCol && startRow <= endRow {
        // top row
        for i := startCol; i <= endCol; i++ {
            m[startRow][i] = count
            count++
        }
        startRow++

        // row col ttb
        for i := startRow; i <= endRow; i++ {
            m[i][endCol] = count
            count++
        }
        endCol--

        // bottom row rtl
        for i := endCol; i >= startCol; i-- {
            m[endRow][i] = count
            count++
        }
        endRow--

        // first col bottom-to-top
        for i := endRow; i >= startRow; i-- {
            m[i][startCol] = count
            count++
        }
        startCol++
    }

    return m
}
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Running Tests

In the directory, run go test.