ianadiwibowo/central-park

package main

import "fmt"

// https://www.hackerrank.com/challenges/2d-array/problem
// Complete the hourglassSum function below.
func hourglassSum(arr [][]int32) int32 {
    var sums [4][4]int32
    maxSum := int32(-63) // The minimum sum is -9 for all 7 number = -63

    for i := 0; i < 4; i++ {
        for j := 0; j < 4; j++ {
            sums[i][j] = arr[i][j] +
                arr[i][j+1] +
                arr[i][j+2] +
                arr[i+1][j+1] +
                arr[i+2][j] +
                arr[i+2][j+1] +
                arr[i+2][j+2]
            if sums[i][j] > maxSum {
                maxSum = sums[i][j]
            }
        }
    }

    return maxSum
}

func main() {
    arr_cases := [][][]int32{
        {
            {1, 1, 1, 0, 0, 0},
            {0, 1, 0, 0, 0, 0},
            {1, 1, 1, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0},
        },
        {
            {-9, -9, -9, 1, 1, 1},
            {0, -9, 0, 4, 3, 2},
            {-9, -9, -9, 1, 2, 3},
            {0, 0, 8, 6, 6, 0},
            {0, 0, 0, -2, 0, 0},
            {0, 0, 1, 2, 4, 0},
        },
        {
            {1, 1, 1, 0, 0, 0},
            {0, 1, 0, 0, 0, 0},
            {1, 1, 1, 0, 0, 0},
            {0, 0, 2, 4, 4, 0},
            {0, 0, 0, 2, 0, 0},
            {0, 0, 1, 2, 4, 0},
        },
        {
            {-9, -9, -9, -9, -9, -9},
            {-9, -9, -9, -9, -9, -9},
            {-9, -9, -9, -9, -9, -9},
            {-9, -9, -9, -9, -9, -9},
            {-9, -9, -9, -9, -9, -9},
            {-9, -9, -9, -9, -9, -9},
        },
        {
            {9, 9, 9, 9, 9, 9},
            {9, 9, 9, 9, 9, 9},
            {9, 9, 9, 9, 9, 9},
            {9, 9, 9, 9, 9, 9},
            {9, 9, 9, 9, 9, 9},
            {9, 9, 9, 9, 9, 9},
        },
    }
    expectations := []int32{
        7,
        28,
        19,
        -63,
        63,
    }

    for i, v := range arr_cases {
        result := hourglassSum(v)
        fmt.Printf("Passed: %v. Test: %v. Expected: %v. Got: %v.\n",
            result == expectations[i],
            v,
            expectations[i],
            result,
        )
    }
}