oj.uz

Submission #21008

# Submission time Handle Problem Language Result Execution time Memory
21008 2017-03-29T09:18:36 Z model_code Sparklers (JOI17_sparklers) C++11
100 / 100
 76 ms 3916 KB 
#include<iostream>
#include<algorithm>

using namespace std;
typedef long long Int;
Int n, t, k;
Int x[108000];
Int X[108000];
bool dp[2][108000];
Int cnt;

bool check(Int v){
  for(Int i = 0;i < n;i++)X[i] = x[i] - 2 * v * t * i;

  Int gl = k, gr = k;
  for(Int i = k;i >= 0;i--){
    if(X[gl] <= X[i])gl = i;
  }
  for(Int i = k;i < n;i++){
    if(X[gr] >= X[i])gr = i;
  }


  Int l = k, r = k;
  while(true){
    bool change = false;
    Int nl = l;
    while(true){
      if(nl - 1 >= gl && X[nl - 1] >= X[r])nl--;
      else break;
      if(X[nl] >= X[l] || nl == gl)break;
    }
    if(X[nl] >= X[l] && l != nl){
      l = nl;
      change = true;
    }

    Int nr = r;
    while(true){
      if(nr + 1 <= gr && X[nr + 1] <= X[l])nr++;
      else break;
      if(X[nr] <= X[r] || nr == gr)break;
    }
    if(X[nr] <= X[r] && r != nr){
      r = nr;
      change = true;
    }
    if(!change)break;
  }


  if(l != gl || r != gr)return false;

  l = 0;
  r = n-1;
  
  if(X[l] < X[r])return false;
  while(true){
    bool change = false;
    
    Int nl = l;
    while(true){
      if(nl + 1 <= gl && X[nl + 1] >= X[r])nl++;
      else break;
      if(X[nl] >= X[l] || nl == gl)break;
    }
    if(X[nl] >= X[l] && nl != l){
      l = nl;
      change = true;
    }

    Int nr = r;
    while(true){
      if(nr - 1 >= gr && X[nr - 1] <= X[l])nr--;
      else break;
      if(X[nr] <= X[r] || nr == gr)break;
    }
    if(X[nr] <= X[r] && nr != r){
      r = nr;
      change = true;
    }

    if(!change)break;
  }
 
  return (r == gr && l == gl);
}

int main(){
  cin >> n >> k >> t;
  k--;
  for(Int i = 0;i < n;i++){
    cin >> x[i];
  }

  bool same_check = true;
  for(int i = 0;i < n;i++){
    if(x[i] != x[0])same_check = false;
  }
  if(same_check){
    cout << 0 << endl;
    return 0;
  }
  
  Int bottom = 0, top = x[n-1];

  while(top - bottom > 1){
    Int mid = (top + bottom) / 2;
    if(check(mid))top = mid;
    else bottom = mid;
  }
  cout << top << endl;
  return 0;
}

Compilation message

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 3916 KB Output is correct
2 Correct 0 ms 3916 KB Output is correct
3 Correct 0 ms 3916 KB Output is correct
4 Correct 0 ms 3916 KB Output is correct
5 Correct 0 ms 3916 KB Output is correct
6 Correct 0 ms 3916 KB Output is correct
7 Correct 0 ms 3916 KB Output is correct
8 Correct 0 ms 3916 KB Output is correct
9 Correct 0 ms 3916 KB Output is correct
10 Correct 0 ms 3916 KB Output is correct
11 Correct 0 ms 3916 KB Output is correct
12 Correct 0 ms 3916 KB Output is correct
13 Correct 0 ms 3916 KB Output is correct
14 Correct 0 ms 3916 KB Output is correct
15 Correct 0 ms 3916 KB Output is correct
16 Correct 0 ms 3916 KB Output is correct
17 Correct 0 ms 3916 KB Output is correct
18 Correct 0 ms 3916 KB Output is correct
19 Correct 0 ms 3916 KB Output is correct
20 Correct 0 ms 3916 KB Output is correct
21 Correct 0 ms 3916 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 3916 KB Output is correct
2 Correct 0 ms 3916 KB Output is correct
3 Correct 0 ms 3916 KB Output is correct
4 Correct 0 ms 3916 KB Output is correct
5 Correct 0 ms 3916 KB Output is correct
6 Correct 0 ms 3916 KB Output is correct
7 Correct 0 ms 3916 KB Output is correct
8 Correct 0 ms 3916 KB Output is correct
9 Correct 0 ms 3916 KB Output is correct
10 Correct 0 ms 3916 KB Output is correct
11 Correct 0 ms 3916 KB Output is correct
12 Correct 0 ms 3916 KB Output is correct
13 Correct 0 ms 3916 KB Output is correct
14 Correct 0 ms 3916 KB Output is correct
15 Correct 0 ms 3916 KB Output is correct
16 Correct 0 ms 3916 KB Output is correct
17 Correct 0 ms 3916 KB Output is correct
18 Correct 0 ms 3916 KB Output is correct
19 Correct 0 ms 3916 KB Output is correct
20 Correct 0 ms 3916 KB Output is correct
21 Correct 0 ms 3916 KB Output is correct
22 Correct 0 ms 3916 KB Output is correct
23 Correct 0 ms 3916 KB Output is correct
24 Correct 0 ms 3916 KB Output is correct
25 Correct 0 ms 3916 KB Output is correct
26 Correct 0 ms 3916 KB Output is correct
27 Correct 0 ms 3916 KB Output is correct
28 Correct 0 ms 3916 KB Output is correct
29 Correct 0 ms 3916 KB Output is correct
30 Correct 0 ms 3916 KB Output is correct
31 Correct 0 ms 3916 KB Output is correct
32 Correct 0 ms 3916 KB Output is correct
33 Correct 0 ms 3916 KB Output is correct
34 Correct 0 ms 3916 KB Output is correct
35 Correct 0 ms 3916 KB Output is correct
36 Correct 0 ms 3916 KB Output is correct
37 Correct 0 ms 3916 KB Output is correct
38 Correct 0 ms 3916 KB Output is correct
39 Correct 0 ms 3916 KB Output is correct
40 Correct 0 ms 3916 KB Output is correct

Subtask #3
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 3916 KB Output is correct
2 Correct 0 ms 3916 KB Output is correct
3 Correct 0 ms 3916 KB Output is correct
4 Correct 0 ms 3916 KB Output is correct
5 Correct 0 ms 3916 KB Output is correct
6 Correct 0 ms 3916 KB Output is correct
7 Correct 0 ms 3916 KB Output is correct
8 Correct 0 ms 3916 KB Output is correct
9 Correct 0 ms 3916 KB Output is correct
10 Correct 0 ms 3916 KB Output is correct
11 Correct 0 ms 3916 KB Output is correct
12 Correct 0 ms 3916 KB Output is correct
13 Correct 0 ms 3916 KB Output is correct
14 Correct 0 ms 3916 KB Output is correct
15 Correct 0 ms 3916 KB Output is correct
16 Correct 0 ms 3916 KB Output is correct
17 Correct 0 ms 3916 KB Output is correct
18 Correct 0 ms 3916 KB Output is correct
19 Correct 0 ms 3916 KB Output is correct
20 Correct 0 ms 3916 KB Output is correct
21 Correct 0 ms 3916 KB Output is correct
22 Correct 0 ms 3916 KB Output is correct
23 Correct 0 ms 3916 KB Output is correct
24 Correct 0 ms 3916 KB Output is correct
25 Correct 0 ms 3916 KB Output is correct
26 Correct 0 ms 3916 KB Output is correct
27 Correct 0 ms 3916 KB Output is correct
28 Correct 0 ms 3916 KB Output is correct
29 Correct 0 ms 3916 KB Output is correct
30 Correct 0 ms 3916 KB Output is correct
31 Correct 0 ms 3916 KB Output is correct
32 Correct 0 ms 3916 KB Output is correct
33 Correct 0 ms 3916 KB Output is correct
34 Correct 0 ms 3916 KB Output is correct
35 Correct 0 ms 3916 KB Output is correct
36 Correct 0 ms 3916 KB Output is correct
37 Correct 0 ms 3916 KB Output is correct
38 Correct 0 ms 3916 KB Output is correct
39 Correct 0 ms 3916 KB Output is correct
40 Correct 0 ms 3916 KB Output is correct
41 Correct 43 ms 3916 KB Output is correct
42 Correct 0 ms 3916 KB Output is correct
43 Correct 13 ms 3916 KB Output is correct
44 Correct 69 ms 3916 KB Output is correct
45 Correct 69 ms 3916 KB Output is correct
46 Correct 63 ms 3916 KB Output is correct
47 Correct 66 ms 3916 KB Output is correct
48 Correct 59 ms 3916 KB Output is correct
49 Correct 66 ms 3916 KB Output is correct
50 Correct 63 ms 3916 KB Output is correct
51 Correct 63 ms 3916 KB Output is correct
52 Correct 66 ms 3916 KB Output is correct
53 Correct 66 ms 3916 KB Output is correct
54 Correct 69 ms 3916 KB Output is correct
55 Correct 66 ms 3916 KB Output is correct
56 Correct 59 ms 3916 KB Output is correct
57 Correct 63 ms 3916 KB Output is correct
58 Correct 59 ms 3916 KB Output is correct
59 Correct 19 ms 3916 KB Output is correct
60 Correct 76 ms 3916 KB Output is correct
61 Correct 53 ms 3916 KB Output is correct
62 Correct 63 ms 3916 KB Output is correct
63 Correct 63 ms 3916 KB Output is correct
64 Correct 76 ms 3916 KB Output is correct
65 Correct 66 ms 3916 KB Output is correct
66 Correct 63 ms 3916 KB Output is correct
67 Correct 59 ms 3916 KB Output is correct
68 Correct 66 ms 3916 KB Output is correct
69 Correct 69 ms 3916 KB Output is correct