链表查询最大节点

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

struct ListNode {
    int val;
    struct ListNode* next;
};

// 创建链表节点
struct ListNode* createNode(int value) {
    struct ListNode* newNode = (struct ListNode*)malloc(sizeof(struct ListNode));
    newNode->val = value;
    newNode->next = NULL;
    return newNode;
}

// 查找链表中的最大节点值
int findMaxNode(struct ListNode* head) {
    if (head == NULL) {
        return -1; // 如果链表为空，返回一个特殊值表示没有最大值
    }
    int maxVal = head->val;
    struct ListNode* current = head->next;
    while (current!= NULL) {
        if (current->val > maxVal) {
            maxVal = current->val;
        }
        current = current->next;
    }
    return maxVal;
}

// 释放链表内存
void freeList(struct ListNode* head) {
    struct ListNode* current = head;
    while (current!= NULL) {
        struct ListNode* next = current->next;
        free(current);
        current = next;
    }
}

int main() {
    // 创建链表：1 -> 3 -> 2 -> 5 -> 4
    struct ListNode* head = createNode(1);
    head->next = createNode(3);
    head->next->next = createNode(2);
    head->next->next->next = createNode(5);
    head->next->next->next->next = createNode(4);

    int maxValue = findMaxNode(head);
    if (maxValue!= -1) {
        printf("链表中的最大节点值为：%d\n", maxValue);
    } else {
        printf("链表为空，无法找到最大节点值。\n");
    }

    // 释放链表内存
    freeList(head);

    return 0;
}