一道AutoDesk笔试题

 要求是以螺旋形输出矩阵，例如：

输入：3

输出： 1 2 3   
              8 9 4   
              7 6 5 

思想：可以看作一群蚂蚁一直往前走，看到墙或者当前位置已经有蚂蚁时则转弯，转弯方向有4个，否则留一个蚂蚁。

 

#include  < iostream >
#include  < iomanip >
#include  < conio.h  >
using   namespace  std;
#define  MAXLENGTH 11

void  PrintPath( int  a[][MAXLENGTH], int  n)
... {
    int count=1;
    int i=0;
    int j=0;    
    int direction=0;
    while(count<=n*n)
    ...{
        if(a[i][j]==0&&i<MAXLENGTH&&j<MAXLENGTH)
        ...{
            a[i][j]=count;
            if(direction==0)
            ...{
                if(j<MAXLENGTH-1&&a[i][j+1]==0)
                    j++;
                count++;
            }
            else
            if(direction==1)
            ...{
                if(i<MAXLENGTH-1&&a[i+1][j]==0)
                    i++;
                count++;
            }
            else
            if(direction==2)
            ...{
                if(j>0&&a[i][j-1]==0)
                    j--;
                count++;
            }
            else
            if(direction==3)
            ...{
                if(i>0&&a[i-1][j]==0)
                    i--;
                count++;
            }
        }
        else
        ...{
            direction++;
            if(direction>=4)
                direction=direction%4;
            if(direction==0)
            ...{
                if(j<MAXLENGTH-1)
                    j++;
            }
            else
            if(direction==1)
            ...{
                if(i<MAXLENGTH-1)
                    i++;
            }
            else
            if(direction==2)
            ...{
                if(j>0)
                    j--;
            }
            else
            if(direction==3)
            ...{
                if(i>0)
                    i--;
            }
        }
    }
}

void  Display( int  a[MAXLENGTH][MAXLENGTH])
... {
    int count=1;
    for(int i=0;i<MAXLENGTH;i++)
    ...{
        cout<<endl;
        for(int j=0;j<MAXLENGTH;j++)
        ...{
            cout<<setw(4)<<a[i][j]<<setw(4);
            if(count%MAXLENGTH==0)
                cout<<endl;
            count++;
        }
    }
    printf(" ");
}

void  main()
... {
    int a[MAXLENGTH][MAXLENGTH];
    for(int i=0;i<MAXLENGTH;i++)
    ...{
        for(int j=0;j<MAXLENGTH;j++)
        ...{
            a[i][j]=0;
        }
    }
    PrintPath(a,MAXLENGTH);
    Display(a);
    getch();
}