JZ19 顺时针打印矩阵

func helper(matrix *[][]int, result *[]int, start, row, col int) {
    curRow := row - start - 1
    curCol := col - start - 1
    
    // 打印第一行
    for i := start; i <= curCol; i++ {
        *result = append(*result, (*matrix)[start][i])
    }
    
    // 打印最后一列
    if curRow > start {
        for i := start + 1; i <= curRow; i++ {
            *result = append(*result, (*matrix)[i][curCol])
        }
    }
    
    // 打印最后一行
    if curRow > start && curCol > start {
        for i := curCol - 1; i >= start; i-- {
            *result = append(*result, (*matrix)[curRow][i])
        }
    }
    
    //打印第一列
    if curRow > start + 1 && curCol > start {
        for i := curRow - 1; i > start; i-- {
            *result = append(*result, (*matrix)[i][start])
        }
    }
}

func printMatrix( matrix [][]int ) []int {
    // write code here
    if len(matrix) == 0 {
        return []int{}
    }
    if len(matrix[0]) == 0 {
        return []int{}
    }
    var result []int
    start := 0 
    row := len(matrix)
    col := len(matrix[0])
    for row > 2 * start && col > 2 * start {
        helper(&matrix, &result, start, row, col)
        start++
    }
    return result
}