Submission #566473

#	Time	Username	Problem	Language	Result	Execution time	Memory
566473		lorenzoferrari	The Big Prize (IOI17_prize)	C++17	100 / 100	59 ms	624 KiB

prize

// 100/100
#include <bits/stdc++.h>
#include "prize.h"
using namespace std;

int answer = -1;
map<int, array<int, 2>> memo;

array<int, 2> askme(int i) {
  array<int, 2> ans;
  if (memo.find(i) != memo.end()) {
    ans[0] = memo[i][0];
    ans[1] = memo[i][1];
  } else {
    auto v = ask(i);
    ans[0] = v[0];
    ans[1] = v[1];
  }
  memo[i] = {ans[0], ans[1]};
  if (ans[0] + ans[1] == 0) answer = i;
  return ans;
}
int count(int i) { return askme(i)[0] + askme(i)[1]; }

void findall(int l, int r) {
  while (l < r && count(l) != count(r)) {
    if (answer != -1) return;
    if (count(l) > count(r)) {
      --r;
    } else {
      ++l;
    }
  }
  if (l >= r) return;
  int cnt = askme(r)[0] - askme(l)[0];
  if (cnt <= 0) return;
  if (answer != -1) return;
  int m = (l + r) / 2;
  findall(l, m);
  findall(m, r);
}

int find_best(int n) {
  findall(0, n-1);
  return answer;
}

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