1052. Linked List Sorting

测试用例很坑。注意链表为空的情形，并且可能有孤节点。

#include 
#include 
#include 
#include 
#include 
using namespace std;
struct Node
{
    int addr;
    int value;
    int next;
    int tag;
};

bool compare(const Node &s1, const Node &s2)
{
    return s1.value < s2.value;
}

Node linklist[100000];
int main()
{
    int startposition,n;
    int position, value, next;
    list mylist;
    list::const_iterator itr;

    cin >> n >> startposition;
    for(int i = 0; i < n; i++)
    {
        cin >> position >> value >> next;
        linklist[position].addr = position;
        linklist[position].value = value;
        linklist[position].next = next;
        linklist[position].tag = 1;
    }
    for(int i = startposition; i != -1;)
    {
        Node node = linklist[i];
        if(node.tag == 0)
            break;
        mylist.push_back(node);
        i = node.next;
    }
    mylist.sort(compare);

    if(!mylist.empty())
    {
        for(itr = mylist.begin(); itr != mylist.end(); ++itr)
        {
            Node node = (Node)*itr;
            if(itr == mylist.begin())
            {
                printf("%d %05d\n", mylist.size(), node.addr);
                printf("%05d %d ", node.addr, node.value);
            }
            else
                printf("%05d\n%05d %d ", node.addr, node.addr, node.value);
        }
        printf("-1\n");
    }
    else
    {
        if(startposition == -1)
            printf("0 -1\n");
        else
           printf("0 %05d\n", startposition);
    }


    return 0;
}