Submission #282476

#	Time	Username	Problem	Language	Result	Execution time	Memory
282476		doowey	The Big Prize (IOI17_prize)	C++14	20 / 100	111 ms	968 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 solve(int li, int ri){
    if(li > ri) return -1;
    while(li <= ri){
        pii cur = get(li);
        if(cur.fi + cur.se == 0) return li;
        if(cur.fi + cur.se == low){
            break;
        }
        li ++ ;
    }
    while(ri >= li){
        pii cur = get(ri);
        if(cur.fi + cur.se == 0) return ri;
        if(cur.fi + cur.se == low){
            break;
        }
        ri -- ;
    }
    if(li > ri) return -1;
    int has = get(ri).fi - get(li).fi;
    if(has == 0) return -1;
    int cl = li, cr = ri;
    int mid;
    int sol0, sol1;
    while(cl < cr){
        mid = (cl + cr) / 2;
        pii cur = get(mid);
        if(cur.fi + cur.se == 0)
            return mid;
        if(cur.fi + cur.se == low){
            pii lf = get(li);
            pii rf = get(ri);
            sol0 = sol1 = -1;
            if(cur.fi - lf.fi > 0){
                sol0 = solve(li + 1, mid - 1);
            }
            if(rf.fi - cur.fi > 0){
                 sol1 = solve(mid + 1, ri - 1);
            }
            if(sol0 == -1) return sol1;
            return sol0;
        }
        else{
            cr = mid;
        }
    }
    return -1;
}

int find_best(int 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);
    }
	return solve(0, n - 1);
}

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