打印指定顺序矩阵

01 02 03 04
12 13 14 05
11 16 15 06
10 09 08 07
打印如上顺序的矩阵代码

<?php
function sort_matrix($n){
$start_row = 0; $start_col = 0; $end_row = $n - 1; $end_col = $n - 1;
$row = 0; $col = 0; $type = 1;
$matrix_arr = [];

    for($k = 1; $k <= $n * $n; ++$k){
        $matrix_arr[$row][$col] = $k;
        if($type == 1){//第一行                
            ++$col;
        }elseif($type == 2){//最后一列
            ++$row;         
        }elseif($type == 3){//最后一行              
            --$col;
        }elseif($type == 4){//第一列               
            --$row;
        }

        if($type == 1 && $col > $end_col){//遍历未赋值的首行后开始行变量+1
            ++$start_row;
            $row = $start_row;
            $col = $end_col;
            $type = 2;//随后处理最后一列
        }elseif($type == 2 && $row > $end_row){//遍历最后一列后
            --$end_col;
            $row = $end_row;
            $col = $end_col;
            $type = 3;//随后处理最后一行
        }elseif($type == 3 && $col < $start_col){//遍历最后一行后
            --$end_row;
            $row = $end_row;
            $col = $start_col;
            $type = 4;//随后处理第一列
        }elseif($type == 4 && $row < $start_row){//遍历第一列后
            ++$start_col;
            $row = $start_row;
            $col = $start_col;
            $type = 1;//随后处理第一行
        }
    }

    return $matrix_arr;
}
//打印row行,col列矩阵
function print_matrix($matrix_arr, $row, $col){
    for($i = 0; $i < $row; ++$i){
        for($j = 0; $j < $col; ++$j){
            echo sprintf("%02d", $matrix_arr[$i][$j]) . " ";
        }
        echo "<br />";
    }       
}

$n = 4;
$matrix_arr = sort_matrix($n);
print_matrix($matrix_arr, $n, $n);

?>