非递归二叉树的中序遍历

非递归二叉树的中序遍历-计蒜客A1004

A1004

#include<bits/stdc++.h>
#include<time.h>
#include<cctype>
#include<iostream>
#include<ostream>
#include<cstdio>
#include<algorithm>
#include<iomanip>
#include<cstring>
#include<string>
#include<cmath>
#include<stack>
#include<queue>
#include<vector>
#include<set>
#include<map>
using namespace std;
typedef long long ll;
const int inf=0x3f3f3f3f;//1061109567
const int INF=0x7fffffff;//2147483647
const int SUP=0x80000000;//-2147483648
#define MAX 1000000
map<char,char>le,ri;
set<char>se;
vector<char>ans;
void tree(char t)
{
    if(se.find(t)==se.end())return;
    tree(le[t]);
    ans.push_back(t);
    tree(ri[t]);
}
int main()
{
    string s;char rt;
    while(cin>>s)
    {
        se.insert(s[0]);
        if(s[4]=='0')rt=s[0];
        if(s[4]=='1')le[s[2]]=s[0];
        if(s[4]=='2')ri[s[2]]=s[0];
        char c=getchar();
        if(c=='\n')break;
    }
    tree(rt);
    for(int i=0;i<ans.size();i++)
    {
        printf("%s%c",i==0?"\0":" ",ans[i]);
    }
    cout<<endl;
    return 0;
}