郁闷的出纳员

题目描述

思路

Treap树 + 延迟标记

代码

#include <cstdio>
#include <cstring>
#include <ctime>
#include <cstdlib>

const int MAX = 1e5 + 5;
int n, m, rt, tot, pt;
char str[5];
int ans, inf = 0x3f3f3f3f;
struct Node {
	int lc, rc, cnt, size, pri, key, tag;
	#define lc(x) t[x].lc
	#define rc(x) t[x].rc
	#define cnt(x) t[x].cnt
	#define size(x) t[x].size
	#define pri(x) t[x].pri
	#define key(x) t[x].key
	#define tag(x) t[x].tag
	#define add(x) t[x].add
}t[MAX];

void pushdown(int r) {
	if (!tag(r)) return;
	if (lc(r)) {
		key(lc(r)) += tag(r);
		tag(lc(r)) += tag(r);
	} 
	if (rc(r)) {
		key(rc(r)) += tag(r);
		tag(rc(r)) += tag(r);
	}
	tag(r) = 0;
}
void pushup(int r) {
	size(r) = size(lc(r)) + size(rc(r)) + cnt(r);
}
void zig(int &r) {
	pushdown(r);
	pushdown(lc(r));
	int s = lc(r);
	lc(r) = rc(s);
	rc(s) = r;
	size(s) = size(r);
	pushup(r);
	r = s;
}
void zag(int &r) {
	pushdown(r);
	pushdown(rc(r));
	int s = rc(r);
	rc(r) = lc(s);
	lc(s) = r;
	size(s) = size(r);
	pushup(r);
	r = s;
}
void show(int x) {
	printf("%d %d %d %d %d %3d
", size(x), lc(x), rc(x), key(x), pri(x), tag(x));
	if (lc(x)) show(lc(x));
	if (rc(x)) show(rc(x));
}
void insert(int &r, int k) {
	if (!r) { 
		r = ++tot;
		pri(r) = rand(), key(r) = k;
		lc(r) = rc(r) = 0;
		size(r) = cnt(r) = 1;
		tag(r) = 0;
		return;
	} 
	pushdown(r);
	if (k == key(r)) ++cnt(r), pushup(r);
	else if(k < key(r)) {
		insert(lc(r), k);
		pushup(r);
		if (pri(lc(r)) < pri(r)) zig(r); 
	} else {
		insert(rc(r), k);
		pushup(r);
		if (pri(rc(r)) < pri(r)) zag(r); 
	}
}

int del (int &r, int k) {
	int res = 0;
	pushdown(r);
	if (k >= key(r)) {
		if (rc(r) != 0) {
			pushdown(rc(r));
			zag(r);
			res = del(r, k);
			pushup(r);
			return res;
		} else {
			res = size(r);
			r = 0;
			return res;
		}
	}
	res = del(lc(r), k);
	pushup(r);
	return res;		
}

int queryPre(int k) {
	int r = rt, res = inf;
	while (r) {
		pushdown(r);
		if (k >= key(r)) res = key(r), r = rc(r);
		else r = lc(r);
	}
	return res;
}

int queryKth(int k) {
	int r = rt, res = inf;
	if (size(r) < k) return inf;
	while (r) {
		pushdown(r);
		if (size(rc(r)) < k && size(rc(r)) + cnt(r) >= k) return key(r);
		else if (size(rc(r)) >= k) r = rc(r);
		else {
			k -= size(rc(r)) + cnt(r);
			r = lc(r);
		}
	}
	return res;
}

inline int read() {
	int s = 0, f = 1;
	char ch = getchar();
	while (ch < '0' || ch > '9') {
		if (ch == '-') f = -1;
		ch = getchar();
	}
	while (ch >= '0' && ch <= '9') s = s * 10 + ch - '0', ch = getchar();
	return s * f;
}

int main() {
	srand(time(NULL));
	n = read(), m = read();
	for (int i = 1, j, k; i <= n; ++i) {
		scanf("%s", str), j = read();
		// printf("%s %d
", str, j);
		if (str[0] == 'I') {
			if (j >= m) insert(rt, j);
		} else if (str[0] == 'A') {
			tag(rt) += j;
			key(rt) += j;
		} else if (str[0] == 'S') {
			tag(rt) -= j;
			key(rt) -= j;
			k = queryPre(m - 1);
			if (k != inf) ans += del(rt, k);
		} else if (str[0] == 'F') {
			k = queryKth(j);
			if (k != inf) printf("%d
", k);
			else printf("-1
");
		}
	}
	printf("%d
", ans);
	return 0;
}