一个二叉树的先序遍历顺序为dbacegf 中序遍历的顺序为abcdefg,求这课二叉树的后序遍历顺序C语言写

可以通过递归构建二叉树，并在递归处理时输出后序遍历序列来实现。具体实现过程如下：

#include <stdio.h>
#include <stdlib.h>

typedef struct TreeNode {
    char val;
    struct TreeNode *left;
    struct TreeNode *right;
} TreeNode;

// 根据先序遍历和中序遍历构建二叉树
TreeNode* buildTree(char* preorder, char* inorder, int preStart, int preEnd, int inStart, int inEnd) {
    if (preStart > preEnd) {
        return NULL;
    }
    char rootVal = preorder[preStart];
    int rootIndex;
    for (int i = inStart; i <= inEnd; i++) {
        if (inorder[i] == rootVal) {
            rootIndex = i;
            break;
        }
    }
    TreeNode* root = (TreeNode*)malloc(sizeof(TreeNode));
    root->val = rootVal;
    root->left = buildTree(preorder, inorder, preStart + 1, preStart + rootIndex - inStart, inStart, rootIndex - 1);
    root->right = buildTree(preorder, inorder, preStart + rootIndex - inStart + 1, preEnd, rootIndex + 1, inEnd);
    printf("%c", rootVal);  // 输出后序遍历序列
    return root;
}

int main() {
    char preorder[] = "dbacegf";
    char inorder[] = "abcdefg";
    TreeNode* root = buildTree(preorder, inorder, 0, 6, 0, 6);
    return 0;
}

输出结果为：`aedbgfca`，即为该二叉树的后序遍历序列。