[Tree] [洛谷] P1030 求先序排列
先序:根左右
中序:左根右
后序:左右根
//#pragma GCC optimize(2)
#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <string>
#include <cstring>
#include <algorithm>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <ctime>
#include <vector>
#include <fstream>
#include <list>
#include <iomanip>
#include <numeric>
using namespace std;
typedef long long ll;
const int MAXN = 1e6 + 10;
void find(string mid, string lst)
{
if(lst.length() >= 1)
{
int len = lst.length();
char ret = lst[len - 1];
cout<<ret;
string tmidl = "", tmidr = "", tlstl = "", tlstr = "";
int pos = 0;
for(;mid[pos] != ret; pos++);
for(int i = 0; i < pos; i++)
tmidl = tmidl + mid[i];
for(int i = pos + 1; i < len; i++)
tmidr = tmidr + mid[i];
for(int i = 0; i < pos; i++)
tlstl = tlstl + lst[i];
for(int i = pos; i < len - 1; i++)
tlstr = tlstr + lst[i];
find(tmidl, tlstl);
find(tmidr, tlstr);
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
string mid, lst;
cin>>mid>>lst;
find(mid, lst);
return 0;
}