Submission #406962

#	Time	Username	Problem	Language	Result	Execution time	Memory
406962		Peti	The Big Prize (IOI17_prize)	C++14	95.19 / 100	76 ms	384 KiB

prize

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

using namespace std;

const int bont = 511;
int ert = 0;

int megold(int l, int r, vector<int> ansl, vector<int> ansr){
    if(l+1 >= r) return -1;
    //cout<<l<<" "<<r<<"\n";
    int m1 = (l+r)/2;
    int m2 = m1;
    vector<int> ans = ask(m1);
    if(ans[0] + ans[1] == 0) return m1;
    vector<int> ans2 = ans;
    while(m1-1 > l && ans[0]+ans[1] != ert){
        m1--;
        ans = ask(m1);
        if(ans[0] + ans[1] == 0) return m1;
    }
    while(m2+1 < r && ans2[0]+ans2[1] != ert){
        m2++;
        ans2 = ask(m2);
        if(ans2[0] + ans2[1] == 0) return m2;
    }
    return max((ansl[0] < ans[0] ? megold(l, m1, ansl, ans) : -1), (ans2[0] < ansr[0] ? megold(m2, r, ans2, ansr) : -1));
}

int find_best(int n) {
    int s = 500;

    for(int i = 0; i < min(n, 500); i++){
        vector<int> ans = ask(i);
        if(ans[0]+ans[1] == 0) return i;
        ert = max(ert, ans[0]+ans[1]);
    }

    while(s < n){
        vector<int> ans = ask(s);
        if(ans[0]+ans[1] == 0)
            return s;
        while(ans[0]+ans[1] != ert){
            s++;
            ans = ask(s);
            if(ans[0]+ans[1] == 0)
                return s;
        }

        int e = min(s+bont, n-1);
        int s2 = e+1;
        vector<int> ans2 = ask(e);
        if(ans2[0]+ans2[1] == 0)
            return e;
        while(s < e && ans2[0]+ans2[1] != ert){
            e--;
            ans2 = ask(e);
            if(ans2[0]+ans2[1] == 0)
                return e;
        }

        if(ans[0] < ans2[0]){
            int temp = megold(s, e, ans, ans2);
            if(temp != -1)
                return temp;
            /*int l = s, r = e;
            while(l+1 < r){
                int m = (l+r)/2;
                vector<int> ans3 = ask(m);

                if(ans3[0]+ans3[1] == 0) return m;

                if(ans3[0]+ans3[1] != ert || ans3[0] != ans[0])
                    r = m;
                else
                    l = m;
            }
            s = l+2;
            ans = ask(s);
            if(ans[0]+ans[1] == 0) return s;
            while(s < e && ans[0]+ans[1] != ert){
                s++;
                ans = ask(s);
                if(ans[0]+ans[1] == 0)
                    return s;
            }*/
        }

        s = s2;
    }
	return -1;
}

• Subtask 1: 20 / 20
• Subtask 2: 75.19 / 80