[蓝桥杯][历届试题]打印十字图

/*
..$$$$$$$$$$$$$..
..$...........$..
$$$.$$$$$$$$$.$$$
$...$.......$...$
$.$$$.$$$$$.$$$.$
$.$...$...$...$.$
$.$.$$$.$.$$$.$.$
$.$.$...$...$.$.$
$.$.$.$$$$$.$.$.$
$.$.$...$...$.$.$
$.$.$$$.$.$$$.$.$
$.$...$...$...$.$
$.$$$.$$$$$.$$$.$
$...$.......$...$
$$$.$$$$$$$$$.$$$
..$...........$..
..$$$$$$$$$$$$$.. 
*/
#include<stdio.h>
char a[150][150] ;
void DFS(int x,int y,int cur);
void PRINT(int n);
int main(void)
{
    int n,length;
    scanf("%d",&n);
    length=4*n+5;
    for(int i=1;i<=length;i++)
        for(int j=1;j<=length;j++)
            a[i][j]=‘.‘;
    DFS(1,1,n);
    PRINT(n);
}
void DFS(int x,int y,int cur)
{
    if(cur < 0) return ;
    int length = 4*cur+5;
    for(int j=y+2;j<y+2+length-4;j++) a[x][j]=a[x+length-1][j]=‘$‘;
    
    a[x+1][y+2]=‘$‘;  a[x+1][y+length-3]=‘$‘; a[x+length-2][y+2]=‘$‘; a[x+length-2][y+length-3]=‘$‘;
    a[x+2][y+2]=‘$‘;  a[x+2][y+length-3]=‘$‘; a[x+length-3][y+2]=‘$‘; a[x+length-3][y+length-3]=‘$‘;
    a[x+2][y+1]=‘$‘;  a[x+2][y+length-2]=‘$‘; a[x+length-3][y+1]=‘$‘; a[x+length-3][y+length-2]=‘$‘;

    for(int i=x+2;i<x+2+length-4;i++) a[i][y]=a[i][y+length-1]=‘$‘;
    DFS(x+2,y+2,cur-1);    
}
void PRINT(int n)
{
    int length = 4*n+5;
    for(int i=1;i<=length;i++) a[i][length+1]=‘\0‘;
    for(int i=1;i<=length;i++) printf("%s\n",a[i]+1);    
}