Submission #292879

#	Time	Username	Problem	Language	Result	Execution time	Memory
292879		shayan_p	The Big Prize (IOI17_prize)	C++17	97.12 / 100	66 ms	512 KiB

prize

// Oh damn! Suddenly you're free to fly...

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

#define F first
#define S second
#define PB push_back
#define sz(s) int((s).size())
#define bit(n,k) (((n)>>(k))&1)

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;

const int maxn = 2e5 + 10, SQ = 530, mod = 1e9 + 7, inf = 1e9 + 10;

int MX;
int CNT = 0;
int GOOD = 0;

pii ASK(int pos){
    assert(++CNT <= 10000);
    vector<int> v = ask(pos);
    if(v[0] == 0 && v[1] == 0)
	throw pos;
    return {v[0], v[1]};
}
void go(int l, int r, int L, int R){
    if(r-l <= 0 || L >= R)
	return;
    int mid = (l+r) >> 1;
    pii p = ASK(mid);
    if(p.F + p.S == MX){
	go(mid+1, r, p.F, R);
	go(l, mid, L, p.F);
	return;
    }

    assert(++GOOD <= SQ);
    
    int pos = mid + 1;
    while(pos < r){
	pii p = ASK(pos);
	if(p.F + p.S != MX){
	    assert(++GOOD <= SQ);
	    pos++;
	}
	else{
	    go(pos + 1, r, p.F, R);
	    break;
	}
    }
    pos = mid-1;
    while(pos >= l){
	pii p = ASK(pos);
	if(p.F + p.S != MX){
	    assert(++GOOD <= SQ);
	    pos--;
	}
	else{
	    go(l, pos, L, p.F);
	    break;
	}
    }
}

int find_best(int n){
    try{
	for(int i = 0; i < SQ; i++){
	    pii p = ASK(i);
	    MX = max(MX, p.F + p.S);
	}
	go(0, n, 0, MX);
    }
    catch(int ans){
	return ans;
    }
    return -1;
}

• Subtask 1: 20 / 20
• Subtask 2: 77.12 / 80