poj2083 分形（图形的递归）

题目传送门

代码有注释。

#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<sstream>
#include<cstring>
#include<bitset>
#include<cstdio>
#include<string>
#include<deque>
#include<stack>
#include<cmath>
#include<queue>
#include<set>
#include<map>
#define CLR(x,y) memset(x,y,sizeof(x))
#define LC(x) (x<<1)
#define RC(x) ((x<<1)+1)
#define MID(x,y) ((x+y)>>1)
using namespace std;
typedef long long ll;
char s[1003][1003];
int mi(int n){  //计算3次幂
	int ans=1;
	for(int i=1;i<=n;i++)
	{
		ans*=3;
	}
	return ans;
}
void dfs(int n,int x,int y){
	if(n==1){//边界
		s[x][y]='X';
		return;
	}
	int d=mi(n-2);
	dfs(n-1,x,y);//对于每一个基础图形  都是这些位置有符号 这就是递归的精髓了
	dfs(n-1,x,y+2*d);
	dfs(n-1,x+d,y+d);
	dfs(n-1,x+2*d,y);
	dfs(n-1,x+2*d,y+2*d);
}
int main(){
	int n;
	while(scanf("%d",&n),n!=-1)
	{
		int d=mi(n-1);
		for(int i=0;i<d;i++)
		{
			for(int j=0;j<d;j++){
				s[i][j]=' ';//把输出的图先全变成空格   然后只需要修改这幅图里的元素
			}
			s[i][d]='\0';//末尾结束
		}
		dfs(n,0,0);
		for(int i=0;i<d;i++){
			printf("%s\n",s[i]);
		}
		printf("-\n");
	}
}

Fractal

Time Limit: 1000MS		Memory Limit: 30000K
Total Submissions: 11175		Accepted: 4996

Description

A fractal is an object or quantity that displays self-similarity, in a somewhat technical sense, on all scales. The object need not exhibit exactly the same structure at all scales, but the same "type" of structures must appear on all scales. 
A box fractal is defined as below : 

• A box fractal of degree 1 is simply 
  X
• A box fractal of degree 2 is 
  X X 
  X 
  X X
• If using B(n - 1) to represent the box fractal of degree n - 1, then a box fractal of degree n is defined recursively as following 
  

  B(n - 1)        B(n - 1)
  
          B(n - 1)
  
  B(n - 1)        B(n - 1)

Your task is to draw a box fractal of degree n.

Input

The input consists of several test cases. Each line of the input contains a positive integer n which is no greater than 7. The last line of input is a negative integer −1 indicating the end of input.

Output

For each test case, output the box fractal using the 'X' notation. Please notice that 'X' is an uppercase letter. Print a line with only a single dash after each test case.

Sample Input

1
2
3
4
-1

Sample Output

X
-
X X
 X
X X
-
X X   X X
 X     X
X X   X X
   X X
    X
   X X
X X   X X
 X     X
X X   X X
-
X X   X X         X X   X X
 X     X           X     X
X X   X X         X X   X X
   X X               X X
    X                 X
   X X               X X
X X   X X         X X   X X
 X     X           X     X
X X   X X         X X   X X
         X X   X X
          X     X
         X X   X X
            X X
             X
            X X
         X X   X X
          X     X
         X X   X X
X X   X X         X X   X X
 X     X           X     X
X X   X X         X X   X X
   X X               X X
    X                 X
   X X               X X
X X   X X         X X   X X
 X     X           X     X
X X   X X         X X   X X
-