fork download
copy 
  1. //Lib
  2. #include<cstdio>
  3. #include<cstring>
  4. #include<cstdlib>
  5. #include<cmath>
  6. #include<ctime>
  7.  
  8. #include<iostream>
  9. #include<algorithm>
  10. #include<vector>
  11. #include<string>
  12. #include<queue>
  13. #include<stack>
  14. #include<set>
  15. #include<map>
  16. using namespace std;
  17. //Macro
  18. #define rep(i,a,b)  for(int i=a,tt=b;i<=tt;++i)
  19. #define drep(i,a,b) for(int i=a,tt=b;i>=tt;--i)
  20. #define erep(i,e,x) for(int i=x;i;i=e[i].next)
  21. #define irep(i,x)   for(__typeof(x.begin()) i=x.begin();i!=x.end();i++)
  22. #define read()  (strtol(ipos,&ipos,10))
  23. #define sqr(x)  ((x)*(x))
  24. #define pb  push_back
  25. #define PS  system("pause");
  26. typedef long long   ll;
  27. typedef pair<int,int> pii;
  28. const int oo=~0U>>1;
  29. const double inf=1e100;
  30. const double eps=1e-6;
  31. string name="", in=".in", out=".out";
  32. //Var
  33. stack<int> s;
  34. int n,num[1000008],l[1000008],r[1000008],ans;
  35. void Work()
  36. {
  37.     scanf("%d",&n);
  38.     rep(i,1,n)scanf("%d",&num[i]);  
  39.     num[0]=num[n+1]=oo;s.push(0);
  40.     rep(i,1,n)
  41.     {
  42.         while(num[i]>num[s.top()])s.pop();
  43.         l[i]=s.top()+1;
  44.         s.push(i);
  45.     }
  46.     while(!s.empty())s.pop();
  47.     s.push(n+1);
  48.     drep(i,n,1)
  49.     {
  50.         while(num[i]>num[s.top()])s.pop();
  51.         r[i]=s.top()-1; 
  52.         s.push(i);
  53.     }
  54.     rep(i,1,n)
  55.     {
  56.         if(r[i]-l[i]+1>=num[i])
  57.             ans=max(ans,num[i]);
  58.     }
  59.     printf("%d\n",ans);
  60. }
  61. int main()
  62. {
  63. //  freopen((name+in).c_str(),"r",stdin);
  64. //  freopen((name+out).c_str(),"w",stdout);
  65. //  Init();
  66.     Work();
  67.     return 0;
  68. }
Not running #stdin #stdout 0s 0KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
https://ideone.com/k558c
language:
C++ (gcc 8.3)
created:
12 years 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!