Submission #986128

#	Time	Username	Problem	Language	Result	Execution time	Memory
986128		AlphaMale06	The Big Prize (IOI17_prize)	C++14	20 / 100	55 ms	11608 KiB

prize

#include <bits/stdc++.h>

#include "prize.h"

using namespace std;
using ll = long long;

vector<int> ask(int i);

vector<int> a[200006];
int summ = 0;

int indices[30] = {1001, 1112, 1232, 1341, 1423, 1540, 1612, 1740, 1812, 1931, 2035, 2113, 2242, 2334, 2456, 2554, 2656, 2954, 3067, 3187, 3256, 3376, 3434, 3565, 3634, 3787, 3865, 3923};

int solve(int l, int r){
    if(l+1>=r)return 0;
    int cnt = a[l][1]-a[r][1];
    if(cnt==0)return 0;
    int s = l+r>>1;
    if(a[s][0]==-1)a[s]=ask(s);
    if(a[s][0]+a[s][1]==summ)return max(solve(l, s), solve(s, r));
    if(a[s][0]+a[s][1]==0)return s;
    int R = s-1, L = s+1;
    for(int i=s-1; i>=l; i--){
        if(a[i][0]==-1)a[i]=ask(i);
        if(a[i][0]+a[i][1]==0)return i;
        if(a[i][0]+a[i][1]==summ){
            R=i;
            break;
        }
    }
    for(int i=s+1; i<=r; i++){
        if(a[i][0]==-1)a[i]=ask(i);
        if(a[i][0]+a[i][1]==0)return i;
        if(a[i][0]+a[i][1]==summ){
            L=i;
            break;
        }
    }
    return max(solve(l, R), solve(L, r));
}

int find_best(int n){
	if(n<=5000){
        for(int i=0; i<n; i++){
            vector<int> ans = ask(i);
            if(ans[0]==0 && ans[1]==0)return i;
        }
	}
	for(int i=0; i< n; i++){
        a[i].push_back(-1);
	}
	int L = -1, R = -1;
	for(int i=0; i<30; i++){
        int ind = indices[i];
        a[ind] = ask(ind);
        summ=max(summ, a[ind][0]+a[ind][1]);
        if(a[ind][0]+a[ind][1]==0)return ind;
	}
    for(int i=0; i<n; i++){
        a[i]=ask(i);
        if(a[i][0]+a[i][1]==0)return i;
        if(a[i][0]+a[i][1]==summ){
            L=i;
            break;
        }
    }
    for(int i=n-1; i>=0; i--){
        a[i]=ask(i);
        if(a[i][0]+a[i][1]==0)return i;
        if(a[i][0]+a[i][1]==summ){
            R=i;
            break;
        }
    }
    return solve(L, R);
}

Compilation message (stderr)

prize.cpp: In function 'int solve(int, int)':
prize.cpp:19:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   19 |     int s = l+r>>1;
      |             ~^~

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