Submission #789303

#	Time	Username	Problem	Language	Result	Execution time	Memory
789303		enerelt14	The Big Prize (IOI17_prize)	C++14	90 / 100	100 ms	11344 KiB

prize

#include "prize.h"
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <climits>
#include <cmath>
#include <complex>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <vector>
using namespace std;
#define pb push_back
 
const int B = 472;
int val;
 
vector<vector<int>> memo;
vector<int> K(int i) {
	if(memo[i][0] != -1) return memo[i];
	return memo[i] = ask(i);
}
 
vector<int> find(int l, int r){
	vector<int> ans;
	if (l > r)return ans;
	vector<int> x = K(r);
	if (x[0] + x[1] != val){
		ans = find(l, r - 1);
		ans.pb(r);
		return ans;
	}
	int tl = l, tr = r;
	while (tl != tr){
		int mid = (tl + tr) / 2;
		vector<int> y = K(mid);
		if (y[0] + y[1] != val){
			tl = mid + 1;
			continue;
		}
		if (y[1] != x[1])tl = mid + 1;
		else tr = mid;
	}
	if (l == tr)return ans;
	else{
		ans = find(l, tr - 2);
		ans.pb(tr - 1);
		return ans;
	}
}
 
int find_best(int n){
	memo.resize(n, {-1, -1});
	vector<int> non_lolipop, x;
	for (int i = 0; i < B && i < n; i++){
		x = K(i);
		val = max(val, x[0] + x[1]);
	}
	for (int i = 0; i < n; i += B){
		x = find(i, min(n - 1, i + B - 1));
		for (int i = 0; i < x.size(); i++)non_lolipop.pb(x[i]);
	}
	for (int i = 0; i < non_lolipop.size(); i++){
		x = K(non_lolipop[i]);
		if (x[0] + x[1] == 0)return non_lolipop[i];
	}
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:69:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |   for (int i = 0; i < x.size(); i++)non_lolipop.pb(x[i]);
      |                   ~~^~~~~~~~~~
prize.cpp:71:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |  for (int i = 0; i < non_lolipop.size(); i++){
      |                  ~~^~~~~~~~~~~~~~~~~~~~
prize.cpp:62:14: warning: control reaches end of non-void function [-Wreturn-type]
   62 |  vector<int> non_lolipop, x;
      |              ^~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80