相信童鞋們都學過二叉樹後序遍歷。不用多說，直接貼程式碼

#include "_"

_______________<________> __[________________];
__________________ _____(________ _______)
{
    _________________ (_______==- _____________)__________;
    _________________ (__[_______][____________]==- _____________&&__[_______][_____________]==- _____________)
    {
        _________("%d ",_______);
        __________;
    }
    _____(__[_______][____________]);
    _____(__[_______][_____________]);
    _________("%d ",_______);
}
________ ____________________()
{
    ________ ___;
    ___________>>___;
    ______________ (________ ______=_____________;______<=___;++______)
    {
        ________ _,____;
        ___________>>_>>____;
        __[______].___________________(_);
        __[______].___________________(____);
    }
    _____(_____________);
    __________ ____________;
}
 

這什麼鬼？！？（放心，編譯不通過）

不過……

#include <bits/stdc++.h>
using namespace std;
#define ________ int
#define _________ printf
#define __________ return
#define ___________ cin
#define ____________ 0
#define _____________ 1
#define ______________ for
#define _______________ vector
#define ________________ 1005
#define _________________ if
#define __________________ void
#define ___________________ push_back
#define ____________________ main