This is the code Code Submitted I submitted for problem D2problem . I am getting TLE, may anyone help me?

I used manacher’s algorithm to solve this problem.

It’s because you declared MAX to be < 10^6 (the maximum limit).

it’s a deceptive TLE, it’s a memory issue. (I don’t know the specifics, perhaps someone who understands the C++ language better will know, I only assume the rational explanation that it tries to allocate more memory dynamically which results in the excess amount of time taken)

AC on your code!

Same issue I also had :

HI there. I am having the same problem. my solution is O(N) but it is still giving a TLE

Finally got the AC

May you provide link of your code?

and what algorithm did you use?

I have used Manacher’s algorithm to find the longest palindromic substring. Now I have modified it a little to get the longest palindromic substring which either starts on the first character or ends on the last character.

This is my code:

`/*Priyansh Agarwal*/ #include<bits/stdc++.h> using namespace std; #define fastio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL) void manacher_algo(string s,int n) { int *arr=new int[n]; for(int i=0;i<n;i++) arr[i]=0; int center_of_longest=0; int right_limit=0; for(int i=1;i<n-1;i++) { int mirror=2*center_of_longest-i; if(i<right_limit) arr[i]=min(right_limit - i,arr[mirror]); while(s[i+(1+arr[i])]==s[i-(1+arr[i])]) arr[i]++; if(i+arr[i]>right_limit) { center_of_longest=i; right_limit=i+arr[i]; } } int max_length=0; int index=-1; for(int i=1;i<n-1;i++) { if(arr[i]>max_length && i-arr[i]==1) { index=i; max_length=arr[i]; } if(arr[i]>max_length && arr[i]+i==n-2 ) { index=i; max_length=arr[i]; } } int left=index-max_length; int right=index+max_length; for(int i=left;i<right;i++) if(s[i]!='#') cout<<s[i]; delete[] arr; } string prime_string(string s,int n) { string s2="$#"; for(int i=0;i<n;i++) { s2+=s[i]; s2+='#'; } s2+='@'; return s2; } int main() { fastio(); #ifndef ONLINE_JUDGE freopen("Input.txt","r",stdin);freopen("Output.txt","w",stdout); #endif int t; cin>>t; while(t--) { string s; cin>>s; int n=s.length(); int counter=0; string ans=""; for(int i=0;i<n/2;i++) { if(s[i]==s[n-1-i]) { ans+=s[i]; counter++; } else break; } if(counter==n/2) cout<<s<<endl; else { string s2=s.substr(counter,n-2*counter); int len=n-2*counter; string s3=prime_string(s2,len); cout<<ans; manacher_algo(s3,s3.length()); reverse(ans.begin(),ans.end()); cout<<ans<<endl; } } return 0; }`