답안 #549344

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
549344 2022-04-15T15:48:26 Z cig32 커다란 상품 (IOI17_prize) C++17
99.32 / 100
44 ms 1908 KB
#include "prize.h"
 
 
 
 
#include <iostream>
#include <vector>
#include <algorithm>
#include "bits/stdc++.h"
 
using namespace std;
 
int find_best(int n);
std::vector<int> ask(int i);
 
static const int max_q = 5000;
static int n;
static int query_count = 0;
static vector<int> g;
static vector<vector<int> > rank_count;
 
 
 
mt19937 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
 
int find_best(int n) {
  
  if(n <= 5000) {
    for(int i=0; i<n; i++) {
      vector<int> res = ask(i);
      if(res[0] + res[1] == 0) {
        return i;
      }
    }
  }
  int res[n][2];
  for(int i=0; i<n; i++) {
    for(int j=0; j<2; j++) {
      res[i][j] = -1;
    }
  }
  int t = ceil(sqrt(n));
  vector<int> v;
  int goodcnt = 0;
  for(int i=0; i<t; i++) {
    int x;
    
    x = t * i + (t - 1);
    if(x >= n) {
      
      while(1) {
        x = rnd(0, n - 1);
        if(res[x][0] == -1) break;
      }
 
    }
    vector<int> ok = ask(x);
    goodcnt = max(goodcnt, ok[0] + ok[1]);
    res[x][0] = ok[0], res[x][1] = ok[1];
    if(ok[0] + ok[1] == 0) {
      return x;
    }
    //cout << ok[0] + ok[1] << " ";
  }
  //cout << "\n";
  //cout << goodcnt << "\n";
  // solution idea: binary search
  // find all 'good' indices, one of them holds the big prize
  // 450 * log2(450) + C queries?
  vector<int> big;
  for(int i=0; i<n; i++) {
    if(res[i][0] != -1 && res[i][0] + res[i][1] == goodcnt) {
      big.push_back(i);
      //cout << i << " ";
    }
  }
  //cout << "\n";
  //cout << big.size() << "\n";
  queue<pair<pair<int, int>, int> > ranges;
  if(big[0] != 0 && res[big[0]][0] > 0) ranges.push({{0, big[0] - 1}, res[big[0]][0]});
  for(int i=1; i<big.size(); i++) {
    if(big[i-1] + 1 == big[i]) continue;
    if(res[big[i]][0] - res[big[i-1]][0] > 0) ranges.push({{big[i-1] + 1, big[i] - 1}, res[big[i]][0] - res[big[i-1]][0]});
  }
  if(big[big.size() - 1] != n - 1 && res[big[big.size() - 1]][1] > 0) ranges.push({{big[big.size() - 1] + 1, n - 1}, res[big[big.size() - 1]][1]});
  //cout << ranges.size() << "\n";
  while(ranges.size()) {
    pair<pair<int, int>, int> f = ranges.front();
    //cout << "split ["  << f.first.first <<", "<<f.first.second <<"]: " <<f.second << "\n";
    ranges.pop();
    if(f.second * 1.1 >= f.first.second - f.first.first + 1) {
      // just query each one, at most 2 * 450 here
      for(int i = f.first.first; i <= f.first.second; i++) {
        vector<int> qwq = ask(i);
        if(qwq[0] + qwq[1] == 0) return i;
      }
    }
    else {
      int mid = (f.first.first + f.first.second) >> 1;
      vector<int> qwq;
      while(1) {
        if(res[mid][0] == -1) {
          qwq = ask(mid);
          res[mid][0] = qwq[0];
          res[mid][1] = qwq[1];
          if(qwq[0] + qwq[1] == 0) return mid;
          if(qwq[0] + qwq[1] == goodcnt) break;
        }
        mid = rnd(f.first.first, f.first.second);
      }
      /*
      cout << "lchild " <<(f.first.first == 0 ? 0 : res[f.first.first - 1][0]) << ", ";
      cout << "rchild "<<(f.first.second == n - 1 ? 0 : res[f.first.second + 1][1])<<"\n";
      cout << "results "<<qwq[0] <<" " <<qwq[1] << "\n";
      */
      if(f.first.first <= mid - 1 && qwq[0] - (f.first.first == 0 ? 0 : res[f.first.first - 1][0]) > 0) {
        ranges.push({{f.first.first, mid - 1}, qwq[0] - (f.first.first == 0 ? 0 : res[f.first.first - 1][0])});
      }
      if(mid + 1 <= f.first.second && qwq[1] - (f.first.second == n - 1 ? 0 : res[f.first.second + 1][1]) > 0) {
        ranges.push({{mid + 1, f.first.second}, qwq[1] - (f.first.second == n - 1 ? 0 : res[f.first.second + 1][1])});
      }
    }
  }
}

Compilation message

prize.cpp: In function 'int find_best(int)':
prize.cpp:84:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |   for(int i=1; i<big.size(); i++) {
      |                ~^~~~~~~~~~~
prize.cpp:46:15: warning: control reaches end of non-void function [-Wreturn-type]
   46 |   vector<int> v;
      |               ^
prize.cpp: At global scope:
prize.cpp:18:12: warning: 'query_count' defined but not used [-Wunused-variable]
   18 | static int query_count = 0;
      |            ^~~~~~~~~~~
prize.cpp:17:12: warning: 'n' defined but not used [-Wunused-variable]
   17 | static int n;
      |            ^
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 1744 KB Output is correct
2 Correct 6 ms 1832 KB Output is correct
3 Correct 3 ms 1896 KB Output is correct
4 Correct 3 ms 1848 KB Output is correct
5 Correct 4 ms 1908 KB Output is correct
6 Correct 6 ms 1832 KB Output is correct
7 Correct 6 ms 1744 KB Output is correct
8 Correct 6 ms 1828 KB Output is correct
9 Correct 3 ms 1872 KB Output is correct
10 Correct 6 ms 1872 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 1832 KB Output is correct
2 Correct 6 ms 1828 KB Output is correct
3 Correct 4 ms 1868 KB Output is correct
4 Correct 5 ms 1828 KB Output is correct
5 Correct 7 ms 1820 KB Output is correct
6 Correct 6 ms 1824 KB Output is correct
7 Correct 5 ms 1744 KB Output is correct
8 Correct 3 ms 1868 KB Output is correct
9 Correct 4 ms 1832 KB Output is correct
10 Correct 8 ms 1868 KB Output is correct
11 Correct 7 ms 1744 KB Output is correct
12 Correct 6 ms 1736 KB Output is correct
13 Correct 7 ms 1824 KB Output is correct
14 Correct 8 ms 464 KB Output is correct
15 Correct 30 ms 1872 KB Output is correct
16 Correct 40 ms 1864 KB Output is correct
17 Correct 31 ms 1824 KB Output is correct
18 Correct 38 ms 1736 KB Output is correct
19 Correct 27 ms 1836 KB Output is correct
20 Correct 22 ms 1060 KB Output is correct
21 Correct 29 ms 1836 KB Output is correct
22 Correct 30 ms 1828 KB Output is correct
23 Correct 6 ms 1736 KB Output is correct
24 Correct 8 ms 1832 KB Output is correct
25 Correct 31 ms 1736 KB Output is correct
26 Correct 17 ms 1852 KB Output is correct
27 Correct 5 ms 1744 KB Output is correct
28 Correct 34 ms 1840 KB Output is correct
29 Correct 31 ms 1856 KB Output is correct
30 Correct 22 ms 1868 KB Output is correct
31 Correct 38 ms 1832 KB Output is correct
32 Correct 7 ms 1824 KB Output is correct
33 Correct 0 ms 208 KB Output is correct
34 Correct 39 ms 1828 KB Output is correct
35 Correct 7 ms 1828 KB Output is correct
36 Correct 40 ms 1824 KB Output is correct
37 Correct 5 ms 1744 KB Output is correct
38 Correct 4 ms 1860 KB Output is correct
39 Correct 28 ms 1832 KB Output is correct
40 Correct 38 ms 1872 KB Output is correct
41 Correct 44 ms 1832 KB Output is correct
42 Correct 21 ms 1848 KB Output is correct
43 Correct 27 ms 1744 KB Output is correct
44 Correct 35 ms 1840 KB Output is correct
45 Correct 26 ms 1744 KB Output is correct
46 Correct 36 ms 1860 KB Output is correct
47 Correct 26 ms 1808 KB Output is correct
48 Correct 24 ms 1736 KB Output is correct
49 Correct 43 ms 1848 KB Output is correct
50 Correct 39 ms 1832 KB Output is correct
51 Correct 40 ms 1872 KB Output is correct
52 Correct 34 ms 1828 KB Output is correct
53 Correct 8 ms 1816 KB Output is correct
54 Correct 18 ms 1844 KB Output is correct
55 Correct 31 ms 1736 KB Output is correct
56 Correct 37 ms 1744 KB Output is correct
57 Correct 39 ms 1832 KB Output is correct
58 Correct 36 ms 1744 KB Output is correct
59 Correct 36 ms 1744 KB Output is correct
60 Correct 37 ms 1820 KB Output is correct
61 Correct 5 ms 1864 KB Output is correct
62 Correct 6 ms 1744 KB Output is correct
63 Correct 5 ms 1820 KB Output is correct
64 Correct 7 ms 1828 KB Output is correct
65 Correct 4 ms 1744 KB Output is correct
66 Correct 12 ms 1852 KB Output is correct
67 Correct 5 ms 1868 KB Output is correct
68 Correct 9 ms 1832 KB Output is correct
69 Correct 7 ms 1844 KB Output is correct
70 Correct 5 ms 1828 KB Output is correct
71 Correct 34 ms 1864 KB Output is correct
72 Correct 5 ms 1868 KB Output is correct
73 Correct 34 ms 1868 KB Output is correct
74 Correct 39 ms 1872 KB Output is correct
75 Correct 8 ms 1872 KB Output is correct
76 Correct 35 ms 1872 KB Output is correct
77 Correct 38 ms 1872 KB Output is correct
78 Correct 8 ms 1864 KB Output is correct
79 Correct 26 ms 1744 KB Output is correct
80 Correct 34 ms 1872 KB Output is correct
81 Correct 37 ms 1872 KB Output is correct
82 Correct 41 ms 1868 KB Output is correct
83 Correct 7 ms 1744 KB Output is correct
84 Correct 27 ms 1868 KB Output is correct
85 Correct 33 ms 1872 KB Output is correct
86 Correct 11 ms 1864 KB Output is correct
87 Correct 7 ms 1744 KB Output is correct
88 Correct 8 ms 1744 KB Output is correct
89 Correct 10 ms 1868 KB Output is correct
90 Correct 5 ms 1872 KB Output is correct
91 Correct 10 ms 1828 KB Output is correct
92 Correct 8 ms 1868 KB Output is correct
93 Partially correct 38 ms 1864 KB Partially correct - number of queries: 5068
94 Partially correct 42 ms 1744 KB Partially correct - number of queries: 5055
95 Correct 31 ms 1872 KB Output is correct
96 Correct 40 ms 1864 KB Output is correct
97 Correct 30 ms 1860 KB Output is correct