题解 | #二叉树遍历#

#include <iostream>
using namespace std;

struct BTree
{
    char val;
    struct BTree*lchild,*rchild;
    BTree(char c):val(c),lchild(nullptr),rchild(nullptr){};
};

BTree* createBTree(string str1,string str2)
{
    if(str1.length()==0)
    {
        return nullptr;;
    }
    char c=str1[0];
    int pos=str2.find(c);
    BTree*ret=new BTree(c);
    ret->lchild=createBTree(str1.substr(1,pos), str2.substr(0,pos));
    ret->rchild=createBTree(str1.substr(pos+1), str2.substr(pos+1));
    return ret;

}

void postorder(BTree*root)
{
    if(root)
    {
        postorder(root->lchild);
        postorder(root->rchild);
        cout<<root->val;
    }
}

int main() {
    string str1;
    string str2;
    while(cin>>str1>>str2)
    {
        BTree* T=createBTree(str1,str2);
        postorder(T);
        cout<<endl;
    }
    
}
// 64 位输出请用 printf("%lld")