Submission #565314

#	Time	Username	Problem	Language	Result	Execution time	Memory
565314		hoanghq2004	The Big Prize (IOI17_prize)	C++14	90 / 100	84 ms	6056 KiB

prize

#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include "prize.h"

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
//
//static const int max_q = 10000;
//static int n;
//static int query_count = 0;
//static vector<int> g;
//static vector<vector<int> > rank_count;
//
//vector<int> ask(int i) {
//	query_count++;
//	if(query_count > max_q) {
//		cerr << "Query limit exceeded" << endl;
//		exit(0);
//	}
//
//	if(i < 0 || i >= n) {
//		cerr << "Bad index: " << i << endl;
//		exit(0);
//	}
//
//	vector<int> res(2);
//	res[0] = rank_count[g[i] - 1][i + 1];
//	res[1] = rank_count[g[i] - 1][n] - res[0];
//	return res;
//}

int find_best(int n) {
    int tot = 0;
    srand(time(nullptr));
    int m = min(n, 10);
    vector <int> used(n, 0);
    vector <vector <int>> ans(n);
    auto get = [&](int i) {
        if (ans[i].size()) return ans[i];
        ans[i] = ask(i);
        return ans[i];
    };
    while (m--) {
        int i = rand() % n;
        while (used[i]) i = rand() % n;
        used[i] = 1;
        vector <int> cur = get(i);
        tot = max(tot, cur[0] + cur[1]);
    }
    int i = 0;
    while (i < n) {
        vector <int> cur = get(i);
        if (cur[0] + cur[1] != tot) {
            if (cur[0] == 0 && cur[1] == 0) return i;
            ++i;
        }
        int L = i, R = n;
        while (L < R) {
            int mid = L + R + 1 >> 1;
            if (get(mid) == get(i)) L = mid;
            else R = mid - 1;
        }
        i = L + 1;
    }
    assert(0);
}

//
//int main() {
//	cin >> n;
//
//	g.resize(n);
//	for(int i = 0; i < n; i++) {
//		cin >> g[i];
//		if(g[i] < 1) {
//			cerr << "Invalid rank " << g[i] << " at index " << i << endl;
//			exit(0);
//		}
//	}
//
//	int max_rank = *max_element(g.begin(), g.end());
//
//	rank_count.resize(max_rank + 1, vector<int>(n + 1, 0));
//	for(int r = 0; r <= max_rank; r++) {
//		for(int i = 1; i <= n; i++) {
//			rank_count[r][i] = rank_count[r][i - 1];
//			if(g[i - 1] == r)
//			  rank_count[r][i]++;
//		}
//	}
//
//	for(int i = 0; i <= n; i++)
//		for(int r = 1; r <= max_rank; r++)
//			rank_count[r][i] += rank_count[r - 1][i];
//
//	int res = find_best(n);
//	cout << res << endl << "Query count: " << query_count << endl;
//
//	return 0;
//}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:65:29: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   65 |             int mid = L + R + 1 >> 1;
      |                       ~~~~~~^~~

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80