Submission #615741

#	Time	Username	Problem	Language	Result	Execution time	Memory
615741		IvanJ	The Big Prize (IOI17_prize)	C++17	0 / 100	71 ms	95608 KiB

prize

#include<bits/stdc++.h>
#include "prize.h"

#define pb push_back
#define x first
#define y second

using namespace std;

typedef pair<int, int> ii;

const int maxn = 2e6 + 5;

vector<int> A[maxn];
vector<int> V;

void find(int lo, int hi) {
	return;
	int mid = (lo + hi) / 2;
	if(A[mid].size() == 0) A[mid] = ask(mid);
	if(A[mid][0] + A[mid][1] < A[hi][0] + A[hi][1]) {V.pb(mid);return;}
	if(A[mid][1] == A[hi][1]) hi = mid;
	else lo = mid + 1;
}

void solve(int lo, int hi, int R) {
	if(lo >= hi) return;
	if(R == 0) return;
	if(R == 1) {find(lo, hi);return;}
	
	int mid = (lo + hi) / 2;
	int mid1 = mid;
	while(1) {
		if(A[mid1].size() == 0) A[mid1] = ask(mid1);
		if(A[mid1][0] + A[mid1][1] < A[hi][0] + A[hi][1]) V.pb(mid1), mid1--;
		else break;
		if(mid1 < lo) break;
	}
	
	int R2 = A[mid1][1] - A[hi][1];
	int R1 = R - R2;
	solve(lo, mid1, R1);
	solve(mid + 1, hi, R2);
}

int find_best(int n) {
	if(n <= 5000) {
		for(int i = 0;i < n;i++) {
			A[i] = ask(i);
			if(A[i][0] + A[i][1] == 0) return i;
		}
	}
	int pos = -1;
	int s = 500;
	for(int i = n - 1;i >= n - s;i--) {
		A[i] = ask(i);
		if(pos == -1 || A[i][0] + A[i][1] > A[pos][0] + A[pos][1])
			pos = i;
	}
	
	for(int i = pos + 1;i < n;i++) V.pb(i);
	solve(0, pos, A[pos][0]);
	for(int i : V) {
		if(A[i].size() == 0) A[i] = ask(i);
		if(A[i][0] + A[i][1] == 0) return i;
	}
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:67:1: warning: control reaches end of non-void function [-Wreturn-type]
   67 | }
      | ^

• Subtask 1: 0 / 20
• Subtask 2: 0 / 80