Cacher is the code snippet organizer for pro developers

func check(grid [][]int, x, y int) int {
    hash := [16]int{}
    hash[grid[x-1][y-1]]++
    hash[grid[x-1][y]]++
    hash[grid[x-1][y+1]]++
    hash[grid[x][y-1]]++
    hash[grid[x][y]]++
    hash[grid[x][y+1]]++
    hash[grid[x+1][y-1]]++
    hash[grid[x+1][y]]++
    hash[grid[x+1][y+1]]++
    for i := 1; i < 10; i++ {
        if hash[i] != 1 {
            return 0
        }
    }
    if grid[x-1][y-1]+grid[x-1][y]+grid[x-1][y+1] != 15 {
        return 0
    }
    if grid[x-1][y-1]+grid[x][y-1]+grid[x+1][y-1] != 15 {
        return 0
    }
    if grid[x-1][y-1]+grid[x][y]+grid[x+1][y+1] != 15 {
        return 0
    }
    if grid[x][y-1]+grid[x][y]+grid[x][y+1] != 15 {
        return 0
    }
    if grid[x+1][y-1]+grid[x+1][y]+grid[x+1][y+1] != 15 {
        return 0
    }
    if grid[x+1][y-1]+grid[x][y]+grid[x-1][y+1] != 15 {
        return 0
    }
    if grid[x-1][y+1]+grid[x][y+1]+grid[x+1][y+1] != 15 {
        return 0
    }
    return 1
}

func numMagicSquaresInside(grid [][]int) int {
    sum := 0
    for i := 1; i < len(grid)-1; i++ {
        for j := 1; j < len(grid[0])-1; j++ {
            if grid[i][j] == 5 {
                sum += check(grid, i, j)
            }
        }
    }
    return sum
}