打印螺旋序列

题目：给定一个数N（N = M^2 - 1）输出0、1、……、N的螺旋序列，其中M为正整数。

例如M为5时，输出如下序列。

0      1     2     3     4
15   16   17   18   5
14   23   24   19   6
13   22   21   20   7
12   11   10   9     8

解法：考虑设定一个(M + 2)^2大小的二维数组，边界部分赋值为-1，便于打印的时候识别边界，中间部分螺旋赋值。代码如下。

[cpp]
#include <iostream>

#define MAX_BASE 100

using namespace std;

void fill_and_print(int _base)
{
    int total = _base * _base;
    int tofill[MAX_BASE + 2][MAX_BASE + 2];
    memset(tofill, 0, sizeof(int) * (MAX_BASE + 2) * (MAX_BASE + 2));
    tofill[0][0] = tofill[0][_base + 1] = tofill[_base + 1][0] = tofill[_base + 1][_base + 1] = -1;
    for(int countBase = 0; countBase < _base; ++countBase)
    {
        tofill[0][countBase + 1] = -1;
        tofill[_base + 1][countBase + 1] = -1;
        tofill[countBase + 1][0] = -1;
        tofill[countBase + 1][_base + 1] = -1;
    }
    int direction = 0; // 0 means right, 1 means down, 2 means left, 3 means up
    int initColumn = 1;
    int initRow = 2;
    tofill[1][1] = -1;
    for(int count = 1; count < total; ++count)
    {
        switch(direction)
        {
            case 0:
                if(tofill[initColumn][initRow + 1] != 0)
                {
                    tofill[initColumn++][initRow] = count;
                    direction = 1;
                }
                else
                {
                    tofill[initColumn][initRow++] = count;
                }
                break;
            case 1:
                if(tofill[initColumn + 1][initRow] != 0)
                {
                    tofill[initColumn][initRow--] = count;
                    direction = 2;
                }
                else
                {
                    tofill[initColumn++][initRow] = count;
                }
                break;
            case 2:
                if(tofill[initColumn][initRow - 1] != 0)
                {
                    tofill[initColumn--][initRow] = count;
                    direction = 3;
                }
                else
                {
                    tofill[initColumn][initRow--] = count;
                }
                break;
            case 3:
                if(tofill[initColumn - 1][initRow] != 0)
                {
                    tofill[initColumn][initRow++] = count;
                    direction = 0;
                }
                else
                {
                    tofill[initColumn--][initRow] = count;
                }
                break;
            default:
                break;
        }
    }
    tofill[1][1] = 0;
    // pr

补充：软件开发 , C++ ,