求二叉树叶子结点到根节点的路径用栈实现用c语言实现

以下是使用栈实现二叉树叶子结点到根节点路径的 C 语言代码：

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

#define MAX_STACK_SIZE 100

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

typedef struct Stack {
    TreeNode* data[MAX_STACK_SIZE];
    int top;
} Stack;

void push(Stack* stack, TreeNode* node) {
    if (stack->top < MAX_STACK_SIZE) {
        stack->data[stack->top++] = node;
    }
}

TreeNode* pop(Stack* stack) {
    if (stack->top > 0) {
        return stack->data[--stack->top];
    }
    return NULL;
}

void printPath(Stack* stack) {
    while (stack->top > 0) {
        TreeNode* node = pop(stack);
        printf("%d ", node->val);
    }
    printf("\n");
}

void leafToRootPath(TreeNode* root) {
    if (!root) {
        return;
    }
    Stack stack;
    stack.top = 0;
    TreeNode* curr = root;
    TreeNode* lastVisited = NULL;
    while (curr || stack.top > 0) {
        if (curr) {
            push(&stack, curr);
            curr = curr->left;
        } else {
            TreeNode* peekNode = stack.data[stack.top - 1];
            if (peekNode->right && lastVisited != peekNode->right) {
                curr = peekNode->right;
            } else {
                if (!peekNode->left && !peekNode->right) {
                    printPath(&stack);
                }
                lastVisited = pop(&stack);
            }
        }
    }
}

int main() {
    /* 构建一棵二叉树 */
    TreeNode* root = (TreeNode*)malloc(sizeof(TreeNode));
    root->val = 1;
    root->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->val = 2;
    root->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->val = 3;
    root->left->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->left->val = 4;
    root->left->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->right->val = 5;
    root->right->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->left->val = 6;
    root->right->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->right->val = 7;

    /* 输出叶子结点到根节点的路径 */
    printf("叶子结点到根节点的路径：\n");
    leafToRootPath(root);

    /* 释放内存 */
    free(root->left->left);
    free(root->left->right);
    free(root->left);
    free(root->right->left);
    free(root->right->right);
    free(root->right);
    free(root);

    return 0;
}

以上代码使用了非递归的方式遍历二叉树，通过栈来保存从根节点到叶子结点的路径，当遍历到叶子结点时，打印出栈中保存的路径即可。