Submission #302100

#	Time	Username	Problem	Language	Result	Execution time	Memory
302100		dantoh000	The Big Prize (IOI17_prize)	C++14	20 / 100	56 ms	416 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int mx = 0;
int ans = -1;
void search(int ll, int lr, int rl, int rr, int cl, int cr, int c){
    if (ans != -1 || c == 0) return;
    int CL, CR;
    if (ll == rr){
        vector<int> p = ask(ll);
        CL = p[0], CR = p[1];
        if (CL + CR != mx){ /// is special
            if (CL == 0 && CR == 0) ans = ll;
        }
        return;
    }
    if (ll < 0 || rr < 0 || rl < 0 || lr < 0 || ll > rr || ll > lr || rl > rr) return;
    int q = (rr-rl)>(lr-ll)?rl:lr;
    vector<int> p = ask(q);
    CL = p[0], CR = p[1];
    if (CL + CR != mx){ /// is special
        if (CL == 0 && CR == 0) {
            ans = q; return;
        }
        else{
            if (q == lr){
                search(ll, lr-1, rl, rr, cl, cr, c-1);
            }
            else if (q == rl){
                search(ll, lr, rl+1, rr, cl, cr, c-1);
            }
        }
        return;
    }
    CR -= cr;
    CL -= cl;
    if (q == lr){
        int L, R, mid;
        L = ll, R = lr-1;
        mid = (L+R)/2;
        search(L, mid, mid+1, R, cl, CR + cr, CL);
        L = rl, R = rr;
        mid = (L+R)/2;
        search(L, mid, mid+1, R, CL + cl, cr, CR);
    }
    else{
        int L, R, mid;
        L = ll, R = lr;
        mid = (L+R)/2;
        search(L, mid, mid+1, R, cl, CR + cr, CL);
        L = rl+1, R = rr;
        mid = (L+R)/2;
        search(L, mid, mid+1, R, CL + cl, cr, CR);
    }

}
int find_best(int n) {

    for (int i = 0; i < min(n,231); i++){
        vector<int> p = ask(i);
        if (p[0] == 0 && p[1] == 0) return i;
        mx = max(mx,p[0]+p[1]);
    }
    int L, R;
    L = 0, R = n-1;
    int mid = (L+R)/2;
    search(L, mid, mid+1, R, 0, 0, mx);
	return ans;
}

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