構建一個值的型別為int的二叉搜尋樹，輸入N和M，然後進行N次插入操作，每次插入之後進行一次遍歷驗證程式碼正確性。然後進行M次刪除操作，每次刪除之後進行一次遍歷驗證程式碼正確性。

#include "bits/stdc++.h"
using namespace std;
typedef long long LL;
const int INF = 0x3f3f3f3f;
struct BST {
    int value;
    BST* lson;
    BST* rson;
}* root;
void remove(int value);
BST* init(int val) {
    BST
 
* point = (BST*)malloc(sizeof(BST));
    point->value = val;
    point->lson = point->rson = NULL;
    return point;
}
void insert(int val) {
    BST* father = NULL;
    BST* now = root;
    while (now != NULL) {
        if (now->value == val) {
            return;
        }
        father 
 
= now;
        if (now->value < val) {
            now = now->rson;
        } else {
            now = now->lson;
        }
    }
    if (father == NULL) {
        root = init(val);
    } else if (father->value < val) {
        father->rson = init(val);
    } else {
        father
 
->lson = init(val);
    }
}
/*這題的難點在於刪除一個節點，思路是:
  當要刪除的節點右子樹不為空時，用右子樹中的最小值代替要刪除的節點的值，同時刪除右子樹中值最小的節點
  否則右子樹為空，可以用左子樹代替當前位置
  當要刪除的節點是唯一節點時,將root置為空
*/
int findAndRemoveMin(BST* point) {
    while (point->lson != NULL) {
        point = point->lson;
    }
    int ans = point->value;
    remove(ans);
    return ans;
}
void remove(int value) {
    BST* father = NULL;
    BST* now = root;
    while (now != NULL) {
        if (now->value == value) {
            if (now->rson != NULL) {
                now->value = findAndRemoveMin(now->rson);
            } else {
                if (father == NULL) {
                    root = NULL;
                } else if (now->value > father->value) {
                    father->rson = now->lson;
                } else {
                    father->lson = now->lson;
                }
                free(now);
            }
            return;
        }
        father = now;
        if (now->value < value) {
            now = now->rson;
        } else {
            now = now->lson;
        }
    }
}
//二叉搜尋樹中序遍歷後會得到一個升序數列，這裡用遞迴寫起來很方便；
void ergodic(BST* point) {
    if (point == NULL) {
        return;
    }
    ergodic(point->lson);
    printf("%d ", point->value);
    ergodic(point->rson);
}
int main() {
    int N, M, value;
    scanf("%d%d", &N, &M);
    while (N--) {
        scanf("%d", &value);
        insert(value);
        ergodic(root);
        puts("");
    }
    while (M--) {
        scanf("%d", &value);
        remove(value);
        ergodic(root);
        puts("");
    }
    return 0;
}