spoj中的运行时错误（SBANK） - 使用红黑树

Question

我正在尝试使用红黑树解决spoj（http://www.spoj.com/problems/SBANK/）中的SBANK问题。当我尝试提交解决方案时，我不断收到RUNTIME（SIGSEGV）错误。

此外，我无法在任何在线判断中使用此红黑树的实现（下面给出的代码）（不断得到相同的错误）。我试过调试代码但找不到它的来源。

有人可以帮我调试吗？

#include<bits/stdc++.h>
using namespace std;

struct node
{
    string key;
    int rep;
    char color;
    struct node *parent,*llink, *rlink;
};


class rbtree
{
    struct node *root;

    public:

        rbtree()
        {
            root = NULL;
        }

        void left_rotate(node *nn)
        {
            struct node *temp = nn->rlink;
            nn->rlink = temp->llink;
            if(temp->llink != NULL)
                temp->llink->parent = nn;

            temp->parent = nn->parent;

            if(temp->parent == NULL)
                root = temp;
            else if(nn == nn->parent->llink)
                nn->parent->llink = temp;
            else
                nn->parent->rlink = temp;

            temp->llink = nn;
            nn->parent = temp;
            temp = NULL;
            delete temp;
        }


        void right_rotate(node *nn)
        {
            struct node *temp = nn->llink;
            nn->llink = temp->rlink;
            if(temp->rlink != NULL)
                temp->rlink->parent = nn;
            temp->parent = nn->parent;
            if(temp->parent == NULL)
                root = temp;
            else if(nn = nn->parent->llink)
                temp = nn->parent->llink;
            else
                temp = nn->parent->rlink;
            temp->rlink = nn;
            nn->parent = temp;
            temp = NULL;
            delete temp;
        }


        void insert_fixup(struct node *nn)
        {
            while(nn != root && nn->parent->color == 'r')
            {
                struct node *uncle;
                if(nn->parent == root)
                    uncle = NULL;
                else if(nn->parent == nn->parent->parent->llink)
                    uncle = nn->parent->parent->rlink;
                else
                    uncle = nn->parent->parent->llink;

                if(uncle != NULL && uncle->color == 'r')
                {
                    nn->parent->color = 'b';
                    uncle->color = 'b';
                    nn->parent->parent->color = 'r';
                    nn = nn->parent->parent;
                }
                else
                {
                    if(nn->parent == nn->parent->parent->llink)
                    {
                        if(nn == nn->parent->llink)
                        {
                            char ch = nn->parent->parent->color;
                            nn->parent->parent->color = nn->parent->color;
                            nn->parent->color = ch;
                            right_rotate(nn->parent->parent);
                        }
                        else
                        {
                            char ch = nn->parent->parent->color;
                            nn->parent->parent->color = nn->color;
                            nn->color = ch;
                            left_rotate(nn->parent);
                            right_rotate(nn->parent->parent);
                        }
                    }
                    else
                    {
                        if(nn == nn->parent->rlink)
                        {
                            char ch = nn->parent->parent->color;
                            nn->parent->parent->color = nn->parent->color;
                            nn->parent->color = ch;
                            left_rotate(nn->parent->parent);
                        }
                        else
                        {
                            char ch = nn->parent->parent->color;
                            nn->parent->parent->color = nn->color;
                            nn->color = ch;
                            right_rotate(nn->parent);
                            left_rotate(nn->parent->parent);
                        }
                    }
                }
            }
            root->color = 'b';
        }

        void insert(string key)
        {
            struct node *cur,*parent,*newnode;
            newnode = new node;
            newnode->key = key;
            newnode->rep = 1;
            newnode->color = 'r';
            newnode->llink = NULL;
            newnode->rlink = NULL;
            newnode->parent = NULL;

            if(root == NULL)
                root = newnode;
            else
            {
                cur = root;
                while(cur != NULL)
                {
                    parent = cur;
                    if(cur->key == key)
                    {
                        cur->rep++;
                        return;
                    }
                    else if(cur->key > key)
                        cur = cur->llink;
                    else
                        cur = cur->rlink;
                }
                if(parent->key > key)
                {
                    parent->llink = newnode;
                    newnode->parent = parent;
                }
                else
                {
                    parent->rlink = newnode;
                    newnode->parent = parent;
                }
            }
            insert_fixup(newnode);
            newnode = NULL;
            delete newnode;
        }

        void print()
        {
            inorder(root);
        }

        void inorder(node *nn)
        {
            if(nn != NULL)
            {
                inorder(nn->llink);
                cout<<nn->key<<" "<<nn->rep<<endl;
                inorder(nn->rlink);
            }
            nn = NULL;
            delete nn;
        }

        void destroy(node *nn)
        {
            if(nn != NULL)
            {
                destroy(nn->llink);
                destroy(nn->rlink);
                if( nn != root)
                    delete nn; 
            }
        }

        void del()
        {
            destroy(root);
            delete root;
        }
};

int main()
{
    int t;
    scanf("%d",&t);
    int n;
    string s;
    char c;
    while(t--)
    {
        rbtree tree;
        scanf("%d",&n);
        scanf("%c",&c);
        while(n--)
        {
            getline(cin,s);
            s.erase(s.end()-1);
            tree.insert(s);
        }
        tree.print();
        tree.del();
        printf("\n");
    }
    return 0;
}