使用C语言和数据结构来编写代码

好的，下面是使用C语言和数据结构来编写交换二叉树中每个节点左右孩子位置的代码：

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

// 定义二叉树节点结构体
typedef struct TreeNode {
    int val;
    struct TreeNode* left;
    struct TreeNode* right;
} TreeNode;

// 定义栈结构体
typedef struct Stack {
    TreeNode** data;
    int top;
    int size;
} Stack;

// 初始化栈
Stack* initStack(int size) {
    Stack* stack = (Stack*)malloc(sizeof(Stack));
    stack->data = (TreeNode**)malloc(sizeof(TreeNode*) * size);
    stack->top = -1;
    stack->size = size;
    return stack;
}

// 判断栈是否为空
int isEmpty(Stack* stack) {
    return stack->top == -1;
}

// 判断栈是否已满
int isFull(Stack* stack) {
    return stack->top == stack->size - 1;
}

// 入栈
void push(Stack* stack, TreeNode* node) {
    if (isFull(stack)) {
        return;
    }
    stack->top++;
    stack->data[stack->top] = node;
}

// 出栈
TreeNode* pop(Stack* stack) {
    if (isEmpty(stack)) {
        return NULL;
    }
    TreeNode* node = stack->data[stack->top];
    stack->top--;
    return node;
}

// 交换二叉树中每个节点左右孩子位置
TreeNode* invertTree(TreeNode* root) {
    if (!root) {
        return NULL;
    }

    Stack* stack = initStack(1000);
    push(stack, root);
    TreeNode* prev = NULL;

    while (!isEmpty(stack)) {
        TreeNode* node = stack->data[stack->top];

        if ((!node->left && !node->right) || (prev && (node->left == prev || node->right == prev))) {
            TreeNode* temp = node->left;
            node->left = node->right;
            node->right = temp;
            pop(stack);
        }
        else {
            if (node->right) {
                push(stack, node->right);
            }
            if (node->left) {
                push(stack, node->left);
            }
        }

        prev = node;
    }

    return root;
}

// 构建二叉树
TreeNode* buildTree() {
    TreeNode* root = (TreeNode*)malloc(sizeof(TreeNode));
    root->val = 1;

    TreeNode* node1 = (TreeNode*)malloc(sizeof(TreeNode));
    node1->val = 2;

    TreeNode* node2 = (TreeNode*)malloc(sizeof(TreeNode));
    node2->val = 3;

    TreeNode* node3 = (TreeNode*)malloc(sizeof(TreeNode));
    node3->val = 4;

    TreeNode* node4 = (TreeNode*)malloc(sizeof(TreeNode));
    node4->val = 5;

    root->left = node1;
    root->right = node2;
    node1->left = node3;
    node1->right = node4;
    node2->left = NULL;
    node2->right = NULL;
    node3->left = NULL;
    node3->right = NULL;
    node4->left = NULL;
    node4->right = NULL;

    return root;
}

// 后序遍历二叉树
void postorder(TreeNode* root) {
    if (!root) {
        return;
    }
    postorder(root->left);
    postorder(root->right);
    printf("%d ", root->val);
}

int main() {
    TreeNode* root = buildTree();
    root = invertTree(root);
    postorder(root);
    return 0;
}

在上述代码中，我们使用了栈来实现后序遍历，并在遍历时交换每个节点的左右孩子。在 `main` 函数中，我们首先构建了一个二叉树，然后调用 `invertTree` 函数进行左右孩子位置交换，最后再进行后序遍历，验证是否交换成功。