Submission #525556

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
525556	2022-02-12T00:00:05 Z	obokaman	The Big Prize (IOI17_prize)	C++17	100 / 100	243 ms	712 KB

prize

#include <iostream>
#include <vector>
#include <set>
#include <map>
#include "prize.h"
#include <random>

using namespace std;


std::default_random_engine generator;

set<int> seen;

typedef pair<int,int> pii;
struct Info {
  int lefthighercount = 0;
  int righthighercount = 0;
};

typedef map<int, Info> Level;
map<int, Level> levels;

void debug() {
  cerr << "Seen: ";
  for (int x: seen) cerr << x << " ";
  cerr << endl;
  cerr << "Levels: " << endl;
  for (auto& s: levels) {
    cerr << "v=" << s.first << ": ";
    for (auto& p: s.second) {
      cerr << p.first << "(" << p.second.lefthighercount << ","
           << p.second.righthighercount << ") ";
    }
    cerr << endl;
  }
  cerr << endl;
}

int count(int a, int b) {
  auto itfrom = seen.lower_bound(a);
  auto itto = seen.lower_bound(b);
  int num=0;
  while (itfrom != itto) {
    ++num;
    ++itfrom;
  }
  return num;
}


// Randomly find some interval in level within [ca,cb) that
// is a good candidate to query.
pii findinterval(int ca, int cb, const Level& l) {
  auto it = l.upper_bound(ca);
  --it;
  //  cerr << "Level" << endl;
  vector<pii> candidates;
  while(it->first + 1 < cb) {
    int a = it->first + 1;
    int lefta = it->second.lefthighercount;
    ++it;
    int b = it->first;
    int leftb = it->second.lefthighercount;
    if (a == b) continue;
    //    int l = b - a;  // #spots
    //   l -= count(seen, a, b);  // l = #empty spots
    int goodones = leftb - lefta;
    //    cerr << "[" << a << "," << b << "): " << goodones << " goodones" << endl;
    if (goodones > 0 && (count(a, b) < b - a)) {
      candidates.push_back({a, b});
    }
  }
  if (candidates.size() == 0) {
    return {-1, -1};
  }
  uniform_int_distribution<int> distribution(0, candidates.size()-1);
  auto p = candidates[distribution(generator)];
  return {max(p.first, ca), min(p.second, cb)};
}


int find_best(int n) {
  while (1) {
    //        debug();
    //    cerr << "XXX" << endl;
    int a = 0, b = n;
    if (!seen.empty()) {
      do {
        a = 0, b = n;
        for (auto it = levels.begin(); it != levels.end(); ++it) {
          tie(a, b) = findinterval(a, b, it->second);
          //          cerr << "Level " << it->first << ": [" << a << "," << b << ")"
          //   << endl;
          if (a == -1 && b == -1) break;
        }
        //        cerr << "." << endl;
      } while (a == -1 && b == -1);
    }
    // find best spot in [a, b)
    int m = (a+b)/2;
    int next = 1;
    int signnext = 1;
    //    cerr << "Checking " << m << "..." << endl;
    while (m < a || m >= b || seen.find(m) != seen.end()) {
      m += signnext * next;
      ++next;
      signnext *= -1;
      //cerr << "Taken. Checking " << m << "..." << endl;
    }
    auto q = ask(m);
    seen.insert(m);
    int v = q[0]+q[1];
    if (v == 0) return m;
    auto& s = levels[v];
    if (s.empty()) {
      s[-1] = Info{0, q[0]+q[1]};
      s[n] = Info{q[0]+q[1], 0};
    }
    s[m] = Info{q[0], q[1]};
  }
}

// int find_best(int n) {
//   int m = n/2;
//   auto q = ask(m);
//   seen.insert(m);
//   int v = q[0]+q[1];
//   if (v == 0) return m;
//   {
//     auto& s = intervals[v];
//     s[-1] = Info{0, q[0]+q[1]};
//     s[m] = Info{q[0], q[1]};
//     s[n] = Info{q[0]+q[1], 0};
//   }
//   while (1) {
//     debug();
//     auto its = intervals.end();
//     --its;
//     auto& s = its->second;
//     double bestscore = 0;
//     auto bestit = s.end();
//     for (auto it = s.begin(); it->first != n;) {
//       int a = it->first + 1;
//       int lefta = it->second.lefthighercount;
//       ++it;
//       int b = it->first;
//       int leftb = it->second.lefthighercount;
//       int l = b - a;  // #spots
//       l -= count(seen, a, b);  // l = #empty spots
//       cerr << "[" << a << "," << b << "): " << l << " empty   ";
//       int goodones = leftb - lefta;
//       cerr << goodones << " goodones" << endl;
//       if (l > 0 || goodones > 0) {
//         if (goodones > 0) {
//           double score = ((double)goodones)/(l+1);
//           if (score > bestscore) {
//             bestit = it;
//             bestscore = score;
//             cerr << "bestscore: " << bestscore << endl;
//           }
//         }
//       }
//     }
//     // find best spot in [ita, itb)
//     auto ita = bestit, itb = bestit;
//     --ita;
//     int a = ita->first+1;
//     int b = itb->first;
//     int m = (a+b)/2;
//     int next = 1;
//     int signnext = 1;
//     while (m < a || m >= b || seen.find(m) != seen.end()) {
//       m += signnext * next;
//       ++next;
//       signnext *= -1;
//     }
//     auto q = ask(m);
//     seen.insert(m);
//     int v = q[0]+q[1];
//     if (v == 0) return m;
//     auto& s2 = intervals[v];
//     if (s2.empty()) {
//       s2[-1] = Info{0, q[0]+q[1]};
//       s2[n] = Info{q[0]+q[1], 0};
//     }
//     s2[m] = Info{q[0], q[1]};
//   }
// }



// int find_best(int n) {
//   if (segments.empty()) {
//     int m = n/2;
//     auto q = ask(m);
//     int v = q[0]+q[1];
//     if (v == 0) return m;
//     segments[v][{0, m}] = Info{q[0], 0, q[1]};
//     segments[v][{m+1, n}] = Info{q[1], q[0], 0};
//   }
//   while (1) {
//     auto its = segments.end();
//     --its;
//     auto& s = its->second;
//     double bestp = 0;
//     auto bestit = s.end();
//     for (auto it = s.begin(); it != s.end(); ++it) {
//       int l = it->first.second - it->first.first;
//       if (l > 0) {
//         double p = ((double)it->second.higher)/l;
//         if (p>bestp) {
//           bestit = it;
//           bestp = p;
//         }
//       }
//     }
//     auto x = bestit->first;
//     auto oldinfo = bestit->second;
//     int m = (x.first+x.second)/2;
//     auto q = ask(m);
//     int v = q[0] + q[1];
//     if (v == 0) return m;
//     // fix here, different v.
//     s.erase(bestit);
//     s[{x.first, m}] = Info{q[0]-oldinfo.leftsum, oldinfo.leftsum, q[1]};
//     s[{m+1, x.second}] = Info{q[1]-oldinfo.rightsum, q[0], oldinfo.rightsum};
//   }
//   return -1;
// }

Subtask #1

20.0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	344 KB	Output is correct
2	Correct	1 ms	200 KB	Output is correct
3	Correct	1 ms	284 KB	Output is correct
4	Correct	1 ms	200 KB	Output is correct
5	Correct	1 ms	280 KB	Output is correct
6	Correct	1 ms	200 KB	Output is correct
7	Correct	1 ms	280 KB	Output is correct
8	Correct	0 ms	200 KB	Output is correct
9	Correct	1 ms	200 KB	Output is correct
10	Correct	2 ms	200 KB	Output is correct

Subtask #2

80.0 / 80.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	200 KB	Output is correct
2	Correct	1 ms	200 KB	Output is correct
3	Correct	1 ms	292 KB	Output is correct
4	Correct	1 ms	200 KB	Output is correct
5	Correct	1 ms	200 KB	Output is correct
6	Correct	1 ms	200 KB	Output is correct
7	Correct	0 ms	200 KB	Output is correct
8	Correct	1 ms	200 KB	Output is correct
9	Correct	1 ms	200 KB	Output is correct
10	Correct	1 ms	200 KB	Output is correct
11	Correct	3 ms	284 KB	Output is correct
12	Correct	4 ms	300 KB	Output is correct
13	Correct	5 ms	328 KB	Output is correct
14	Correct	10 ms	284 KB	Output is correct
15	Correct	8 ms	268 KB	Output is correct
16	Correct	74 ms	712 KB	Output is correct
17	Correct	38 ms	424 KB	Output is correct
18	Correct	47 ms	428 KB	Output is correct
19	Correct	12 ms	320 KB	Output is correct
20	Correct	27 ms	404 KB	Output is correct
21	Correct	40 ms	448 KB	Output is correct
22	Correct	21 ms	388 KB	Output is correct
23	Correct	1 ms	276 KB	Output is correct
24	Correct	5 ms	260 KB	Output is correct
25	Correct	77 ms	420 KB	Output is correct
26	Correct	35 ms	404 KB	Output is correct
27	Correct	1 ms	280 KB	Output is correct
28	Correct	13 ms	332 KB	Output is correct
29	Correct	51 ms	404 KB	Output is correct
30	Correct	41 ms	408 KB	Output is correct
31	Correct	26 ms	396 KB	Output is correct
32	Correct	7 ms	280 KB	Output is correct
33	Correct	1 ms	200 KB	Output is correct
34	Correct	39 ms	376 KB	Output is correct
35	Correct	2 ms	200 KB	Output is correct
36	Correct	59 ms	448 KB	Output is correct
37	Correct	3 ms	276 KB	Output is correct
38	Correct	1 ms	276 KB	Output is correct
39	Correct	27 ms	284 KB	Output is correct
40	Correct	6 ms	280 KB	Output is correct
41	Correct	124 ms	480 KB	Output is correct
42	Correct	112 ms	504 KB	Output is correct
43	Correct	72 ms	536 KB	Output is correct
44	Correct	103 ms	448 KB	Output is correct
45	Correct	26 ms	276 KB	Output is correct
46	Correct	28 ms	404 KB	Output is correct
47	Correct	16 ms	352 KB	Output is correct
48	Correct	102 ms	508 KB	Output is correct
49	Correct	69 ms	468 KB	Output is correct
50	Correct	29 ms	320 KB	Output is correct
51	Correct	94 ms	408 KB	Output is correct
52	Correct	103 ms	448 KB	Output is correct
53	Correct	1 ms	260 KB	Output is correct
54	Correct	3 ms	280 KB	Output is correct
55	Correct	14 ms	272 KB	Output is correct
56	Correct	40 ms	392 KB	Output is correct
57	Correct	30 ms	404 KB	Output is correct
58	Correct	155 ms	464 KB	Output is correct
59	Correct	67 ms	388 KB	Output is correct
60	Correct	32 ms	320 KB	Output is correct
61	Correct	1 ms	200 KB	Output is correct
62	Correct	2 ms	200 KB	Output is correct
63	Correct	1 ms	260 KB	Output is correct
64	Correct	1 ms	200 KB	Output is correct
65	Correct	1 ms	200 KB	Output is correct
66	Correct	1 ms	200 KB	Output is correct
67	Correct	1 ms	200 KB	Output is correct
68	Correct	1 ms	268 KB	Output is correct
69	Correct	1 ms	264 KB	Output is correct
70	Correct	1 ms	200 KB	Output is correct
71	Correct	243 ms	672 KB	Output is correct
72	Correct	9 ms	312 KB	Output is correct
73	Correct	218 ms	624 KB	Output is correct
74	Correct	67 ms	424 KB	Output is correct
75	Correct	2 ms	200 KB	Output is correct
76	Correct	51 ms	488 KB	Output is correct
77	Correct	99 ms	460 KB	Output is correct
78	Correct	7 ms	212 KB	Output is correct
79	Correct	64 ms	380 KB	Output is correct
80	Correct	132 ms	584 KB	Output is correct
81	Correct	172 ms	448 KB	Output is correct
82	Correct	46 ms	392 KB	Output is correct
83	Correct	2 ms	200 KB	Output is correct
84	Correct	45 ms	436 KB	Output is correct
85	Correct	160 ms	592 KB	Output is correct
86	Correct	4 ms	456 KB	Output is correct
87	Correct	2 ms	296 KB	Output is correct
88	Correct	3 ms	200 KB	Output is correct
89	Correct	2 ms	284 KB	Output is correct
90	Correct	1 ms	200 KB	Output is correct
91	Correct	2 ms	200 KB	Output is correct
92	Correct	1 ms	200 KB	Output is correct
93	Correct	4 ms	200 KB	Output is correct
94	Correct	7 ms	308 KB	Output is correct
95	Correct	4 ms	200 KB	Output is correct
96	Correct	3 ms	292 KB	Output is correct
97	Correct	1 ms	200 KB	Output is correct