fork download
copy 
  1. //Believe in yourself ,( try and try and then try ), You can do it 
  2. //You don't have to be great to start but you have to start to be great 
  3. #include <iostream>
  4. #include<algorithm>
  5. #include<cmath>
  6. #include<string>
  7. #include<vector>
  8. #include <utility>
  9. #include <stack>
  10. #include <set>
  11. #include <map>
  12. #include<queue>
  13. #include<set>
  14. // 2D vector vector<vector<int>>v(n,vector<int>(m));
  15. // sort and reverse in vector sort(v.begin(), v.end(), greater<int>());
  16. // str.erase(pos,len); erase in string
  17. // a = s.substr(0, i)<<before i, b = s.substr(i)<<from i to end;
  18. // cout << (v[0] == 1 ? "YES" : "NO") << endl;
  19. // unsigned long long int
  20. // priority_queue<ll, vector<ll>, greater<ll>> p;
  21. using namespace std;
  22. #define ll long long
  23. #define all(c)  c.begin(),c.end()
  24.  
  25.  
  26. ll gcd(ll a, ll b)
  27. {
  28.     while (b != 0)
  29.     {
  30.         ll a2 = a;
  31.         a = b;        b = a2 % b;
  32.     }
  33.     return  a;
  34. }
  35.  
  36. ll lcm(ll a, ll b)
  37. {
  38.     return a / gcd(a, b) * b;
  39. }
  40.  
  41. void soso()
  42. {
  43.     ios::sync_with_stdio(0);
  44.     cin.tie(NULL);
  45.     cout.tie(NULL);
  46. }
  47. int n, k; ll arr[200005];
  48.  
  49. bool can(ll mid)
  50. {
  51.     ll cnt = 0,cnt2=0,m=0,temp=mid; 
  52.     for (int i = 0; i < n; i+=2)
  53.     {
  54.         if (mid >= arr[i])
  55.         {
  56.             mid--;  cnt++;
  57.         }
  58.     }
  59.     for (int i = 1; i < n; i += 2)
  60.     {
  61.         if (temp >= arr[i])
  62.         {
  63.             temp--; cnt2++;
  64.         }
  65.     }
  66.     m = max(cnt, cnt2);
  67.     return (m >= k);
  68. }
  69. int main()
  70. {
  71.     soso();
  72.     cin >> n >> k;
  73.     for (int i = 0; i < n; i++)cin >> arr[i];
  74.     sort(arr, arr + n);
  75.     ll l = 1, r = 1e18, ans = -1;
  76.     while (l <= r)
  77.     {
  78.         ll mid = (l + r) / 2;
  79.         if (can(mid))
  80.         {
  81.             ans = mid; r = mid - 1;
  82.         }
  83.         else l = mid + 1;
  84.     }
  85.     cout << ans;
  86. }
Success #stdin #stdout 0.01s 5300KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
1
https://ideone.com/VYctC5
language:
C++ (gcc 8.3)
created:
16 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!