Treap Demo

#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>#include <algorithm>#include <string>#include <stdlib.h>using namespace std;struct Node {Node *ch[2];int priority;int val;int cmp(int x) const {if (val == x) return -1;return x < val ? 0 : 1;}};class Treap {public:Node *root;Treap() {root = NULL;}void rotate(Node *&o, int d) {// d: 0, then rotate left// d: 1, then rotate rightNode *k = o->ch[d^1];if (k == NULL) return; o->ch[d^1] = k->ch[d];k->ch[d] = o;o = k;}int random() {return rand() % 57;}void insert(Node *&o, int val) {if (o == NULL) {o = new Node(); o->val = val; o->priority = random(); o->ch[0] = o->ch[1] = NULL;} else {int d = o->cmp(val);insert(o->ch[d], val);if (o->ch[d]->priority < o->priority) rotate(o, d^1);}}void remove(Node *&o, int val) {if (o == NULL) return;if (o->cmp(val) == -1) {if (o->ch[0] == NULL) o = o->ch[1];else if (o->ch[1] == NULL) o = o->ch[0];else {int d = o->ch[0]->priority < o->ch[1]->priority?0:1;rotate(o, d^1);remove(o->ch[d^1], val);}} else {remove(o->ch[o->cmp(val)], val);}}Node* find(Node *o, int val) {while (o != NULL) {int d = o->cmp(val);if (d == -1) return o;o = o->ch[d];}return NULL;}};int main() {Treap t;int sz[6] = {2, 4, 5, 7, 9, 10};for (int i = 0; i < 6; i++) t.insert(t.root, sz[i]);t.remove(t.root, 7);return 0;}