求链表中奇数位置上的和

给出一个链表，每个节点有一个数值，你需要返回链表奇数位置的数值之和，位置从1开始计数。

例如链表为1->2->4->5->6你需要返回11

#include<stdio.h>
#include <algorithm>
using namespace std;

struct ListNode{
    int val;
    ListNode *next;
    ListNode():val(0), next(NULL){};
    ListNode(int val):val(val), next(NULL){}
};

//you just need submit this function
int oddSum(ListNode *head){
    //place your code here
}

int main(){
    int size = rand() % 1000 + 1;
    ListNode *dummy = new ListNode(0);
    ListNode *prev = dummy;
    int middleValue = 0, sum = 0;
    for (int i = 1; i <= size; i++){
        int val = rand() % 100000;
        if (i % 2) sum += val;
        ListNode *temp = new ListNode(val);
        prev->next = temp;
        prev = temp;
    }

    if (sum == oddSum(dummy->next)){
        puts("YES");
    } else{
        puts("NO");
    }
    return 0;
}

代码实现：

#include<iostream>
#include<algorithm>
using namespace std;

struct ListNode{
    int val;
    ListNode *next;
    ListNode():val(0), next(NULL){};
    ListNode(int val):val(val),next(NULL){};
};

//每次都让 指针p 走两步，直到走完整个链表 
int oddSum(ListNode *head)
{
    int result = 0;
    ListNode *p = head;
    while(p != NULL){
        result += p->val;
        p = p->next->next;
    }
    return result;
}


int main()
{
    int size = rand() % 1000 + 1;
    ListNode *dummy = new ListNode(0);
    ListNode *prev = dummy;
    int middleValue = 0, sum = 0;
    for(int i = 1; i <= size; i++){
        int val = rand() % 100000;
        if(i % 2)
            sum += val;
        ListNode *temp = new ListNode(val);
        prev->next = temp;
        prev = temp;
    }
    if(sum == oddSum(dummy->next)){
        puts("YES");
    }else{
        puts("NO");
    }
    return 0;
}