Submission #607745

#	Time	Username	Problem	Language	Result	Execution time	Memory
607745		cheissmart	Teams (IOI15_teams)	C++14	34 / 100	4046 ms	24404 KiB

teams

#include "teams.h"
#pragma GCC optimize("Ofast")
#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;

// 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);
// }

namespace wt { // wavelet tree
	int a[N];
	void build() {
	}
	int qry(int l, int r, int x) { // [l, r]
		int ans = 0;
		for(int i = l; i <= r; i++)
			ans += a[i] < x;
		return ans;
	}
	int find_who(int l, int r, int need) {
		vi b;
		for(int i = l; i <= r; i++)
			b.PB(a[i]);
		sort(ALL(b));
		return b[need];
	}
}

V<pi> aux;
int as_lb[N], as_rb[N];

int qry(int lb, int rb, int x) { // # of elements < x in [lb, rb]
	lb = as_lb[lb], rb = as_rb[rb];
	if(lb > rb) return 0;
	return wt::qry(lb, rb, x); // [lb, rb]
}

int find_who(int lb, int rb, int need) {
	lb = as_lb[lb], rb = as_rb[rb];
	assert(lb <= rb);
	return wt::find_who(lb, rb, need); // [lb, rb]
} 
 
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++)
		aux.EB(l[p[i]], i);
	sort(ALL(aux));
	for(int i = 0; i < n; i++)
		wt::a[i] = aux[i].S;
	wt::build();
	for(int i = 1; i <= n; i++) {
		as_lb[i] = lower_bound(ALL(aux), pi(i, -INF)) - aux.begin();
		as_rb[i] = upper_bound(ALL(aux), pi(i, INF)) - aux.begin() - 1;
	}
}

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, j = 0; i < m; i++) {
		int need = 0, ii = i;
		while(i < m && a[i] == a[ii]) need += a[i++];
		i--;

		while(j < n && r[p[j]] < a[i]) j++;
		while(stk.back().hi < j) {
			assert(SZ(stk));
			stk.pop_back();
		}
		int 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);
			int cnt = qry(lb + 1, rb, stk.back().hi) - qry(lb + 1, rb, at_least);
			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(lb + 1, rb, at_least);
				int who = find_who(lb + 1, rb, need + dead);
				stk.PB({a[i], who});
				break;
			}
		}
		if(stk.empty()) return 0;
	}
	return 1;
}

Compilation message (stderr)

teams.cpp: In function 'void init(int, int*, int*)':
teams.cpp:85:49: warning: conversion from '__gnu_cxx::__normal_iterator<std::pair<int, int>*, std::vector<std::pair<int, int> > >::difference_type' {aka 'long int'} to 'int' may change value [-Wconversion]
   85 |   as_lb[i] = lower_bound(ALL(aux), pi(i, -INF)) - aux.begin();
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
teams.cpp:86:62: warning: conversion from '__gnu_cxx::__normal_iterator<std::pair<int, int>*, std::vector<std::pair<int, int> > >::difference_type' {aka 'long int'} to 'int' may change value [-Wconversion]
   86 |   as_rb[i] = upper_bound(ALL(aux), pi(i, INF)) - aux.begin() - 1;
      |              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~

• Subtask 1: 21 / 21
• Subtask 2: 13 / 13
• Subtask 3: 0 / 43
• Subtask 4: 0 / 23