Submission #250271

#	Time	Username	Problem	Language	Result	Execution time	Memory
250271		fedoseevtimofey	The Big Prize (IOI17_prize)	C++14	20 / 100	1585 ms	1048580 KiB

prize

#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <random>
#include <iomanip>
#include <functional>
#include <cassert>

using namespace std;

typedef long long ll;

#include "prize.h"

int find_best(int n) {
  map <int, vector <int>> mem;
  int cnt = 0;
  auto my_ask = [&] (int i) {
    if (!mem.count(i)) {
      ++cnt;
      assert(cnt <= 10000);
      mem[i] = ask(i);
    }
    return mem[i];
  };
  function <int(int, int)> rec = [&] (int l, int r) {
    if (l > r) return -1;
    auto f = my_ask(l);
    if (f[0] + f[1] == 0) return l;
    auto s = my_ask(r);
    if (s[0] + s[1] == 0) return r;
    bool fl = false;
    if (f[0] + f[1] != s[0] + s[1]) fl = true;
    else if (f[1] - s[1] > 0) fl = true;
    if (fl && l != r) {
      int m = (l + r) >> 1;
      int x = rec(l, m);
      if (x != -1) return x;
      x = rec(m, r);
      return x;
    } else {
      return -1;
    }
  };
  int ans = rec(0, n - 1);
  return ans;
}   

#ifdef LOCAL
const int max_q = 10000;
int n;
int query_count = 0;
vector<int> g;
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 main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
  freopen("input.txt", "r", stdin);
#endif
  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;
}
#endif

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