oj.uz

Submission #63112

# Submission time Handle Problem Language Result Execution time Memory
63112 2018-07-31T18:37:42 Z Arturgo Sparklers (JOI17_sparklers) C++14
100 / 100
 200 ms 29004 KB 
/*
Dichotomie sur la vitesse, puis :

Glouton*/
#include <iostream>
#include <vector>
#include <list>
using namespace std;

bool debug = false;

bool canBeBeaten(vector<long long> a, vector<long long> b) {
  int posG = a.size() - 1, posD = b.size() - 1;
  int nposG = a.size() - 1, nposD = b.size() - 1;

  bool change = true;
  while(change) {
    change = false;
    while(nposG != 0 && a[nposG - 1] + b[posD] <= 0) {
      nposG--;
      if(a[nposG] <= a[posG]) {
	posG = nposG;
	change = true;
      }
    }
    while(nposD != 0 && a[posG] + b[nposD - 1] <= 0) {
      nposD--;
      if(b[nposD] <= b[posD]) {
	posD = nposD;
	change = true;
      }
    }
  }

  long long somme = a[posG] + b[posD];

  int posMinG = 0;
  for(int g = 0;g < (int)a.size();g++) {
    if(a[g] < a[posMinG]) {
      posMinG = g;
    }
  }

  int posMinD = 0;
  for(int d = 0;d < (int)b.size();d++) {
    if(b[d] < b[posMinD]) {
      posMinD = d;
    }
  }

  if(posMinD != posD || posMinG != posG) return false;

  while(a.size() > posG + 1) a.pop_back();
  while(b.size() > posD + 1) b.pop_back();

  vector<long long> maxA;
  vector<long long> maxB;
  
  for(long long elem : a) {
    if(elem + b.back() > 0) {
      return false;
    }
    if(maxA.empty())
      maxA.push_back(elem);
    else
      maxA.push_back(max(elem, maxA.back()));
  }

  for(long long elem : b) {
    if(elem + a.back() > 0) {
      return false;
    }
    if(maxB.empty())
      maxB.push_back(elem);
    else
      maxB.push_back(max(elem, maxB.back()));
  }

  posG = a.size() - 1;
  posD = b.size() - 1;

  if(debug) {
    for(long long elem : a) {
      cout << elem << " ";
    }
    cout << endl;
    for(long long elem : b) {
      cout << elem << " ";
    }
    cout << endl;

    cout << posMinG << " " << posMinD << endl;
    cout << posG << " " << posD << endl;
  }
  
  while(true) {
    if(posG == 0 && posD == 0 && a[0] + b[0] <= 0)
      return true;
    for(int dec = -1;;dec--) {
      int nposG = posG + dec;
      int nposD = posD + dec;

      if(nposD >= 0 && maxA[posG] + b[nposD] <= 0) {
	posD = nposD;
	break;
      }
      if(nposG >= 0 && maxB[posD] + a[nposG] <= 0) {
	posG = nposG;
	break;
      }

      if(nposD < 0 && nposG < 0)
	return false;
    }
  }
}

int nbJoueurs, debut, temps;
vector<int> positions;

bool check(long long value) {
  vector<long long> pileA, pileB;

  for(int iJoueur = 0;iJoueur <= debut;iJoueur++) {
    pileA.push_back(positions[debut] - positions[iJoueur] - 2 * (debut - iJoueur) * value * temps);
  }

  for(int iJoueur = nbJoueurs - 1;iJoueur >= debut;iJoueur--) {
    pileB.push_back(positions[iJoueur] - positions[debut] - 2 * (iJoueur - debut) * value * temps);
  }

  return canBeBeaten(pileA, pileB);
}

int main() {
  cin >> nbJoueurs >> debut >> temps;
  debut--;

  for(int iJoueur = 0;iJoueur < nbJoueurs;iJoueur++) {
    int position;
    cin >> position;
    positions.push_back(position);
  }

  long long deb = -1, fin = 1000 * 1000 * 1000;
  while(fin - deb > 1) {
    long long mil = (deb + fin) / 2;

    if(check(mil)) {
      fin = mil;
    }
    else {
      deb = mil;
    }
  }

  cout << deb + 1 << endl;
  /*debug = true;
    cout << check(deb + 1) << endl;*/

  return 0;
}

Compilation message

sparklers.cpp: In function 'bool canBeBeaten(std::vector<long long int>, std::vector<long long int>)':
sparklers.cpp:53:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(a.size() > posG + 1) a.pop_back();
         ~~~~~~~~~^~~~~~~~~~
sparklers.cpp:54:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(b.size() > posD + 1) b.pop_back();
         ~~~~~~~~~^~~~~~~~~~
sparklers.cpp:35:13: warning: unused variable 'somme' [-Wunused-variable]
   long long somme = a[posG] + b[posD];
             ^~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 608 KB Output is correct
4 Correct 2 ms 608 KB Output is correct
5 Correct 3 ms 608 KB Output is correct
6 Correct 2 ms 608 KB Output is correct
7 Correct 2 ms 608 KB Output is correct
8 Correct 2 ms 608 KB Output is correct
9 Correct 4 ms 608 KB Output is correct
10 Correct 2 ms 608 KB Output is correct
11 Correct 4 ms 608 KB Output is correct
12 Correct 3 ms 608 KB Output is correct
13 Correct 3 ms 608 KB Output is correct
14 Correct 3 ms 628 KB Output is correct
15 Correct 3 ms 652 KB Output is correct
16 Correct 4 ms 652 KB Output is correct
17 Correct 2 ms 652 KB Output is correct
18 Correct 4 ms 652 KB Output is correct
19 Correct 4 ms 652 KB Output is correct
20 Correct 4 ms 696 KB Output is correct
21 Correct 5 ms 696 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 608 KB Output is correct
4 Correct 2 ms 608 KB Output is correct
5 Correct 3 ms 608 KB Output is correct
6 Correct 2 ms 608 KB Output is correct
7 Correct 2 ms 608 KB Output is correct
8 Correct 2 ms 608 KB Output is correct
9 Correct 4 ms 608 KB Output is correct
10 Correct 2 ms 608 KB Output is correct
11 Correct 4 ms 608 KB Output is correct
12 Correct 3 ms 608 KB Output is correct
13 Correct 3 ms 608 KB Output is correct
14 Correct 3 ms 628 KB Output is correct
15 Correct 3 ms 652 KB Output is correct
16 Correct 4 ms 652 KB Output is correct
17 Correct 2 ms 652 KB Output is correct
18 Correct 4 ms 652 KB Output is correct
19 Correct 4 ms 652 KB Output is correct
20 Correct 4 ms 696 KB Output is correct
21 Correct 5 ms 696 KB Output is correct
22 Correct 4 ms 704 KB Output is correct
23 Correct 3 ms 712 KB Output is correct
24 Correct 4 ms 736 KB Output is correct
25 Correct 4 ms 792 KB Output is correct
26 Correct 4 ms 836 KB Output is correct
27 Correct 5 ms 976 KB Output is correct
28 Correct 5 ms 976 KB Output is correct
29 Correct 5 ms 976 KB Output is correct
30 Correct 4 ms 976 KB Output is correct
31 Correct 4 ms 976 KB Output is correct
32 Correct 4 ms 976 KB Output is correct
33 Correct 5 ms 976 KB Output is correct
34 Correct 4 ms 980 KB Output is correct
35 Correct 5 ms 992 KB Output is correct
36 Correct 4 ms 992 KB Output is correct
37 Correct 3 ms 1016 KB Output is correct
38 Correct 5 ms 1028 KB Output is correct
39 Correct 4 ms 1040 KB Output is correct
40 Correct 4 ms 1052 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 608 KB Output is correct
4 Correct 2 ms 608 KB Output is correct
5 Correct 3 ms 608 KB Output is correct
6 Correct 2 ms 608 KB Output is correct
7 Correct 2 ms 608 KB Output is correct
8 Correct 2 ms 608 KB Output is correct
9 Correct 4 ms 608 KB Output is correct
10 Correct 2 ms 608 KB Output is correct
11 Correct 4 ms 608 KB Output is correct
12 Correct 3 ms 608 KB Output is correct
13 Correct 3 ms 608 KB Output is correct
14 Correct 3 ms 628 KB Output is correct
15 Correct 3 ms 652 KB Output is correct
16 Correct 4 ms 652 KB Output is correct
17 Correct 2 ms 652 KB Output is correct
18 Correct 4 ms 652 KB Output is correct
19 Correct 4 ms 652 KB Output is correct
20 Correct 4 ms 696 KB Output is correct
21 Correct 5 ms 696 KB Output is correct
22 Correct 4 ms 704 KB Output is correct
23 Correct 3 ms 712 KB Output is correct
24 Correct 4 ms 736 KB Output is correct
25 Correct 4 ms 792 KB Output is correct
26 Correct 4 ms 836 KB Output is correct
27 Correct 5 ms 976 KB Output is correct
28 Correct 5 ms 976 KB Output is correct
29 Correct 5 ms 976 KB Output is correct
30 Correct 4 ms 976 KB Output is correct
31 Correct 4 ms 976 KB Output is correct
32 Correct 4 ms 976 KB Output is correct
33 Correct 5 ms 976 KB Output is correct
34 Correct 4 ms 980 KB Output is correct
35 Correct 5 ms 992 KB Output is correct
36 Correct 4 ms 992 KB Output is correct
37 Correct 3 ms 1016 KB Output is correct
38 Correct 5 ms 1028 KB Output is correct
39 Correct 4 ms 1040 KB Output is correct
40 Correct 4 ms 1052 KB Output is correct
41 Correct 109 ms 3300 KB Output is correct
42 Correct 7 ms 3300 KB Output is correct
43 Correct 31 ms 3300 KB Output is correct
44 Correct 199 ms 5288 KB Output is correct
45 Correct 147 ms 6148 KB Output is correct
46 Correct 159 ms 7068 KB Output is correct
47 Correct 189 ms 8024 KB Output is correct
48 Correct 154 ms 8884 KB Output is correct
49 Correct 169 ms 9948 KB Output is correct
50 Correct 175 ms 10840 KB Output is correct
51 Correct 162 ms 11896 KB Output is correct
52 Correct 180 ms 13284 KB Output is correct
53 Correct 144 ms 13892 KB Output is correct
54 Correct 183 ms 15336 KB Output is correct
55 Correct 153 ms 15980 KB Output is correct
56 Correct 152 ms 16772 KB Output is correct
57 Correct 149 ms 17600 KB Output is correct
58 Correct 159 ms 18668 KB Output is correct
59 Correct 119 ms 18780 KB Output is correct
60 Correct 174 ms 20348 KB Output is correct
61 Correct 200 ms 21020 KB Output is correct
62 Correct 169 ms 21960 KB Output is correct
63 Correct 167 ms 22936 KB Output is correct
64 Correct 155 ms 23572 KB Output is correct
65 Correct 156 ms 24584 KB Output is correct
66 Correct 153 ms 25408 KB Output is correct
67 Correct 148 ms 26380 KB Output is correct
68 Correct 177 ms 27832 KB Output is correct
69 Correct 181 ms 29004 KB Output is correct