Submission #370293

#	Time	Username	Problem	Language	Result	Execution time	Memory
370293		doowey	The Big Prize (IOI17_prize)	C++14	97.41 / 100	68 ms	876 KiB

prize

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

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

#define fi first
#define se second
#define mp make_pair

map<int,pii> res;

pii get(int x){
    if(res.count(x)) return res[x];
    vector<int> g = ask(x);
    res[x] = mp(g[0], g[1]);
    return mp(g[0],g[1]);
}

int low = 0;
int n;

int solve(int li, int ri, int know){
    if(li > ri || know == 0) return -1;
    pii ash = get(li);
    if(ash.fi + ash.se == 0) return li;
    if(li == ri) return -1;
    int mid = (li + ri + 1) / 2;
    pii qad = get(mid);
    if(qad.fi + qad.se == 0) return mid;
    if(qad.fi + qad.se == low){
        int fa = solve(li, mid - 1, ash.se - qad.se);
        if(fa != -1) return fa;
        int fb = solve(mid, ri, know - (ash.se - qad.se));
        return fb;
    }
    int ca = mid;
    int cb = mid + 1;
    while(ca >= li){
        ash = get(ca);
        if(ash.fi + ash.se == 0) return ca;
        if(ash.fi + ash.se < low){
            ca -- ;
            know -- ;
        }
        else{
            break;
        }
    }
    pii fa = get(li);
    ash = get(ca);
    int faf = fa.se - ash.se;
    int tri = solve(li, ca, faf);
    if(tri != -1) return tri;
    while(cb <= ri){
        ash = get(cb);
        if(ash.fi + ash.se == 0) return cb;
        if(ash.fi + ash.se < low){
            cb ++ ;
            know--;
        }
        else{
            break;
        }
    }
    return solve(cb, ri, know - faf);
}

int find_best(int _n) {
    n = _n;
    pii cur;
    for(int i = 0 ; i < min(n,500); i ++ ){
        cur = get(i);
        if(cur.fi + cur.se == 0)
            return i;
        low = max(low, cur.fi + cur.se);
    }
    int lef = 0, rig = n - 1;
    while(1){
        pii cc = get(lef);
        if(cc.fi + cc.se == 0) return lef;
        if(cc.fi + cc.se != low)
            lef ++ ;
        else
            break;
    }
    while(1){
        pii cc = get(rig);
        if(cc.fi + cc.se == 0) return rig;
        if(cc.fi + cc.se != low)
            rig -- ;
        else
            break;
    }
    pii sa = get(lef);
    pii sb = get(rig);
	return solve(lef, rig, sa.se-sb.se);
}

• Subtask 1: 20 / 20
• Subtask 2: 77.41 / 80