poj 2255 二叉樹的後序遍歷

2015/1/23

根據 二叉樹的先序和中序遍歷建立二叉樹後輸出後序遍歷。

#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<vector>
#include<climits>
#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>

using namespace std;
typedef long long ll;  

#define mod 10007
#define lson pos<<1,l,mid
#define sc(n) scanf("%d",&n)
#define rson pos<<1|1,mid+1,r
#define pr(n) printf("%d\n",n)
#define met(n,m) memset(n, m, sizeof(n))
#define F(x,y,i) for(int i = x;i > y; i--)
#define f(x,y,i) for(int i = x;i < y; i++)
#define ff(x,y,i) for(int i = x;i <= y; i++)
#define FF(x,y,i) for(int i = x;i >= y; i--) 

const int N=100500;
const int inf = INT_MAX;

int Max(int a,int b)
{
	return a>b?a:b;
}

int Min(int a,int b)
{
	return  a<b?a:b;
}

char s1[100],s2[100];

int root[1000],r[1000],l[1000]; 
int len , tp , tot;

int find(int x)
{
	f(0,len,i)
	{
		if(s1[x] == s2[i])
		{
			return i;
		}
	}
	return 0;
}


void bfs(int L,int R)
{
	
	root[tp] = tp;
	int fa = tp;

	int mid = find(tp);

	tp++;
	if(mid  > L)
	{
		
		
		l[fa] =  tp;
		bfs(L,mid-1);
	}
	
	if(mid < R)
	{
		r[fa] =  tp;
		bfs(mid+1,R);
	}
	
}
int sum = 0;
void dfs(int x)
{
  	
	if(l[x])
	{
		dfs(l[x]);
	}
	if(r[x])
	{
		dfs(r[x]);
	}
	
	printf("%c",s1[root[x]]);

}

int main()  
{  
    int n, m, tot, x;
    while(~scanf("%s%s",s1,s2))
    {
    	 len = strlen(s1);
    	 
    	 met(root,0);
  		 met(l,0);
   	  	 met(r,0);
   	     tp = 0;
   	     
	    bfs(0,len-1);

   	 	dfs(0);
   	 	
    	printf("\n");

    }

    return 0;  
}