Submission #608395

#	Time	Username	Problem	Language	Result	Execution time	Memory
608395		cheissmart	Teams (IOI15_teams)	C++14	100 / 100	1628 ms	355612 KiB

teams

#include "teams.h"
#include <bits/stdc++.h>
#define F first
#define S second
#define V vector
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(), (v).end()
 
using namespace std;
 
typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;
 
const int INF = 1e9 + 7, N = 5e5 + 7;
 
int n;
int l[N], r[N];
vi p, rp;
 
struct node {
	node *l, *r;
	int cnt;
	node() { l = r = nullptr; cnt = 0; }
	node (node *_l, node *_r) {
		l = _l, r = _r;
		cnt = (l ? l -> cnt : 0) + (r ? r -> cnt : 0);
	}
};
 
vi ev[N];
 
node* h[N];
 
node* lc(node* t) { return t ? t -> l : nullptr; }
node* rc(node* t) { return t ? t -> r : nullptr; }
int ct(node* t) { return t ? t -> cnt : 0; }
 
node* upd(node* t, int pos, int tl = 0, int tr = n) {
	if(tr - tl == 1) {
		node* tt = new node();
		tt -> cnt = 1;
		return tt;
	}
	int tm = (tl + tr) / 2;
	if(pos < tm) return new node(upd(lc(t), pos, tl, tm), rc(t));
	else return new node(lc(t), upd(rc(t), pos, tm, tr));
}
 
int qry(node* t, int lb, int rb, int tl = 0, int tr = n) {
	if(!t) return 0;
	if(lb <= tl && tr <= rb) return t -> cnt;
	int tm = (tl + tr) / 2;
	int ans = 0;
	if(lb < tm) ans += qry(t -> l, lb, rb, tl, tm);
	if(rb > tm) ans += qry(t -> r, lb, rb, tm, tr);
	return ans;
}
 
int find_who(node* x, node* y, int cnt, int tl = 0, int tr = n) {
	assert(ct(y) - ct(x) > cnt);
	if(tr - tl == 1) return tl;
	int tm = (tl + tr) / 2;
	if(ct(lc(y)) - ct(lc(x)) > cnt)
		return find_who(lc(x), lc(y), cnt, tl, tm);
	else
		return find_who(rc(x), rc(y), cnt - (ct(lc(y)) - ct(lc(x))), tm, tr);
}
 
void init(int _n, int _l[], int _r[]) {
	n = _n;
	for(int i = 0; i < n; i++)
		l[i] = _l[i], r[i] = _r[i];
 
	p = vi(n); iota(ALL(p), 0);
	sort(ALL(p), [&] (int x, int y) {
		return r[x] < r[y];
	});
	for(int i = 0; i < n; i++)
		rp.PB(r[p[i]]);
	for(int i = 0; i < n; i++)
		ev[l[p[i]]].PB(i);
	for(int i = 1; i <= n; i++) {
		h[i] = h[i - 1];
		for(int j:ev[i])
			h[i] = upd(h[i], j);
	}
}
 
struct seg {
	int r, hi;
};
 
int can(int m, int a[]) {
	if(accumulate(a, a + m, 0LL) > n) return 0;
	sort(a, a + m);
 
	V<seg> stk;
	stk.PB({0, n});
	for(int i = 0; i < m; i++) {
		int j = lower_bound(ALL(rp), a[i]) - rp.begin();
		while(stk.back().hi < j) {
			assert(SZ(stk));
			stk.pop_back();
		}
		int need = a[i], at_least = j;
		while(need && SZ(stk)) {
			int lb = stk.back().r, rb = a[i]; // (lb, rb]
			int cnt = qry(h[rb], at_least, stk.back().hi) - qry(h[lb], at_least, stk.back().hi);
			if(cnt < need) {
				at_least = stk.back().hi;
				stk.pop_back();
				need -= cnt;
			} else if(cnt == need) {
				at_least = stk.back().hi;
				stk.pop_back();
				stk.PB({a[i], at_least});
				need -= cnt;
				break;
			} else {
				int dead = qry(h[rb], 0, at_least) - qry(h[lb], 0, at_least);
				int who = find_who(h[lb], h[rb], need + dead);
				stk.PB({a[i], who});
				break;
			}
		}
		if(stk.empty()) return 0;
	}
	return 1;
}

Compilation message (stderr)

teams.cpp: In function 'int can(int, int*)':
teams.cpp:104:38: warning: conversion from '__gnu_cxx::__normal_iterator<int*, std::vector<int> >::difference_type' {aka 'long int'} to 'int' may change value [-Wconversion]
  104 |   int j = lower_bound(ALL(rp), a[i]) - rp.begin();
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~

• Subtask 1: 21 / 21
• Subtask 2: 13 / 13
• Subtask 3: 43 / 43
• Subtask 4: 23 / 23