给定一棵二叉树的前序遍历和中序遍历,求其后序遍历

川长思鸟来 2023-10-08 09:18 266阅读 0赞

#include <stdio.h>
    #include <string.h>
    struct Node{
        
        Node *lChild;
        Node *rChild;
        char c;
    }Tree[50];      //静态内存分配数组
    int loc;        //静态数组中已经分配的结点个数
    Node *creat()
    {
        
        Tree[loc].lChild = Tree[loc].rChild = NULL;
        return &Tree[loc++];
    }
    char str1[30],str2[30];
    void postOrder(Node *T)
    {
        
        if(T->lChild != NULL)
        {
        
            postOrder(T->lChild);
        }
        if(T->rChild != NULL)
        {
        
            postOrder(T->rChild);
        }
        printf("%c",T->c);
    }
    Node *build(int s1,int e1,int s2,int e2)
    {
        
        Node *ret = creat();
        ret->c = str1[s1];
        int rootIdx;
        for(int i = s2;i <= e2;i++)
        {
        
            if(str2[i] == str1[s1])
            {
        
                rootIdx = i;
                break;
            }
        }
        if(rootIdx != s2)
        {
        
            ret->lChild = build(s1 + 1,s1 + (rootIdx - s2),s2,rootIdx - 1);
        }
        if(rootIdx != e2)
        {
        
            ret->rChild = build(s1 + (rootIdx - s2) + 1,e1,rootIdx + 1,e2);
        }
        return ret;
    }
    int main()
    {
        
        while(scanf("%s",str1) != EOF)
        {
        
            scanf("%s",str2);
            loc = 0;
            int L1 = strlen(str1);
            int L2 = strlen(str2);
            Node *T = build(0,L1 - 1,0,L2 - 1);
            postOrder(T);
            printf("\n");
        }
        return 0;
    }