AddressSanitizer:DEADLYSIGNAL
=================================================================
==6820==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000010 (pc 0x55996232e378 bp 0x60300002b948 sp 0x7ffdcf18c7b0 T0)
==6820==The signal is caused by a READ memory access.

看不懂。

题目

Code(79pts)：

#include <cmath>
#include <cstdio>
#include <algorithm>

typedef struct AVLNode {
	int data, height, cnt, size;
	AVLNode *lson, *rson;
	AVLNode():
	    data(0), height(1), cnt(1), size(1), lson(NULL), rson(NULL) {}
    AVLNode(int val):
        data(val), height(1), cnt(1), size(1), lson(NULL), rson(NULL) {}
}*AVLTree;

inline int Height(AVLTree T) {
	if (T == NULL)
		return 0;
	return T -> height;
}
inline int Size(AVLTree T) {
	if (T == NULL)
		return 0;
	return T -> size;
}
inline void Upd_Point(AVLTree &T) {
    T -> size = Size(T -> lson) + Size(T -> rson) + T -> cnt;
    T -> height = std::max(Height(T -> lson), Height(T -> rson)) + 1;
}

inline AVLTree LL_rotate(AVLTree &T) {
	register AVLTree temp = T -> lson;
	T -> lson = temp -> rson;
	temp -> rson = T;
	Upd_Point(T);
	Upd_Point(temp);
	return temp;
}
inline AVLTree RR_rotate(AVLTree &T) {
	register AVLTree temp = T -> rson;
	T -> rson = temp -> lson;
	temp -> lson = T;
	Upd_Point(T);
    Upd_Point(temp);
	return temp;
}
inline AVLTree LR_rotate(AVLTree &T) {
	T -> lson = RR_rotate(T -> lson);
	return LL_rotate(T);
}
inline AVLTree RL_rotate(AVLTree &T) {
	T -> rson = LL_rotate(T -> rson);
	return RR_rotate(T);
}

inline AVLTree Insert(AVLTree &T, int data) {
	if (T == NULL) {
		T = new AVLNode(data);
		return T;
	}
	if (T -> data == data) {
		T -> cnt ++;
		Upd_Point(T);
		return T;
	}
	if (T -> data > data) {
		T -> lson = Insert(T -> lson, data);
		if (Height(T -> lson) - Height(T -> rson) == 2){
			if (data < T -> lson -> data) // 一路向左
				T = LL_rotate(T);
			else
				T = LR_rotate(T);
		}
	} else {
		T -> rson = Insert(T -> rson, data);
		if (Height(T -> rson) - Height(T -> lson) == 2){
			if (data > T -> rson -> data)
				T = RR_rotate(T);
			else
				T = RL_rotate(T);
		}
	}
	Upd_Point(T);
	return T;
}

inline AVLTree Adjust(AVLTree &T) {
	if (T == NULL)
		return NULL;
	if (Height(T -> lson) - Height(T -> rson) == 2) {
		if (Height(T -> lson -> lson) >= Height(T -> lson -> rson))
			T = LL_rotate(T);
		else
			T = LR_rotate(T);
    } else if (Height(T -> rson) - Height(T -> lson) == 2) {
		if (Height(T -> rson -> rson) >= Height(T -> rson -> lson))
			T = RR_rotate(T);
		else
			T = RL_rotate(T);
    }
    Upd_Point(T);
	return T;
}
inline AVLTree Delete(AVLTree &T, int data) {
	if (T == NULL) // 值不存在
		return NULL;
	if (T -> data == data) { // 如果找到这个值
		// 将这个值替换为这个点的直接后驱
		// 实际上前驱也可以
		if (T -> cnt > 1) {
            T -> cnt --;
            Upd_Point(T);
            return T;
		}
		if (T -> rson == NULL) { // 这个节点没有子树上的后驱，把左子树拉上来，这个节点删掉或数量 -1
            register AVLTree temp = T;
            T = T -> lson;
            delete temp;
		} else { // 把子树上的后驱换上来，把后驱删了
			register AVLTree temp;
			temp = T -> rson;
			while (temp -> lson)
				temp = temp -> lson;
			T -> data = temp -> data;
			T -> cnt = temp -> cnt; // 此处有大量改动，检查。
			temp -> cnt = 1;
			T -> rson = Delete(T -> rson, T -> data); // 删后驱
            Upd_Point(T);
		}
		return T;
	} else if (T -> data > data)
		T -> lson = Delete(T -> lson, data);
	else if (T -> data < data)
		T -> rson = Delete(T -> rson, data);
	Adjust(T);
	Upd_Point(T);
	return T;
}

// 一下部分可能按需调整
inline int First_Rank(AVLTree T, int data) { // 查排名
	if (T == NULL)
		return 1;
	if (T -> data == data) // 找到
		return Size(T -> lson) + 1;
	if (T -> data > data) // left tree
		return First_Rank(T -> lson, data);
	return First_Rank(T -> rson, data) + Size(T -> lson) + T -> cnt;
}
inline int kth(AVLTree T, int idx) {
    if (T == NULL)
        return 0;
	if (idx <= Size(T -> lson))
		return kth(T -> lson, idx);
	if (idx <= Size(T -> lson) + T -> cnt)
		return T -> data;
	else
		return kth(T -> rson, idx - Size(T -> lson) - T -> cnt);
}

inline int GetPrev(AVLTree Root, int data) {
    AVLTree ans = new AVLNode(-10000005), T = Root;
    while (T) {
        if (T -> data == data) {
            if (T -> lson) {
                T = T -> lson;
                while (T -> rson)
                    T = T -> rson;
                ans = T;
            }
            break;
        }
        if (T -> data < data && T -> data > ans -> data)
            ans = T;
        T = T -> data > data ? T -> lson : T -> rson;
    }
    return ans -> data;
}
inline int GetNext(AVLTree Root, int data) {
    AVLTree ans = new AVLNode(10000005), T = Root;
    while (T) {
        if (T -> data == data) {
            if (T -> rson) {
                T = T -> rson;
                while (T -> lson)
                    T = T -> lson;
                ans = T;
            }
            break;
        }
        if (T -> data > data && T -> data < ans -> data)
            ans = T;
        T = T -> data > data ? T -> lson : T -> rson;
    }
    return ans -> data;
}

inline void print(AVLTree now) {
	if (now == NULL)
		return;
	print(now -> lson);
	for (int i(1); i <= now -> cnt; i++)
        printf("%d ", now -> data);
    fflush(stdout);
	print(now -> rson);
}

int T, opt, x;

int main() {
    //freopen("input.txt", "r", stdin);
    //freopen("ri.txt", "w", stdout);
	AVLTree Root = NULL;
	scanf("%d", &T);
	while (T--) {
		scanf("%d %d", &opt, &x);
		if (opt == 1)
			Insert(Root, x);
		else if (opt == 2)
			Delete(Root, x);
		else if (opt == 3)
			printf("%d\n", First_Rank(Root, x));
		else if (opt == 4)
			printf("%d\n", kth(Root, x));
		else if (opt == 5)
			printf("%d\n", GetPrev(Root, x));
		else if (opt == 6)
			printf("%d\n", GetNext(Root, x));
        //print(Root);
        //printf("\n");
	}
	return 0;
}