Thanks Bartholomew for the explanation. Always knew this fact about java strings but for the first time got to know the practical implication 😃
On Thu 11 Apr, 2019, 10:16 PM Bartholomew Furrow <[email protected] wrote: > Arindam, > > Strings in Java are immutable, which means they can't change. So when you > say: > > res+=path.charAt(j)=='S'?'E':'S' > > You aren't saying "Java, please add a character to the end of res." > You're saying: "Java, please create a new String by copying over all the > data from res, and adding one character. Then point res at that new String." > If you do that 50,000 times, you end up copying 1+2+3+4+5...+50000 > characters: 1.25 billion, just for one test case. > > Java provides a class called StringBuilder, which lets you build a String > this way in O(N) instead of O(N^2). > > Best, > Bartholomew > > On Thu, Apr 11, 2019 at 7:50 AM Arindam Roy <[email protected]> wrote: > >> Hi, >> >> Can anyone help me in understanding why the following code is TLE for the >> hidden test case: >> >> import java.util.*; >> import java.io.*; >> public class Solution { >> public static void main(String[] args) { >> Scanner in = new Scanner(new BufferedReader(new >> InputStreamReader(System.in))); >> int t = Integer.parseInt(in.nextLine()); >> for (int i = 1; i <= t; ++i) { >> in.nextLine(); //ignore grid size >> String path = in.nextLine(); >> String res = ""; >> for(int j=0;j<path.length();j++) { >> res+=path.charAt(j)=='S'?'E':'S'; >> } >> System.out.println("Case #" + i + ": " + res); >> } >> } >> } >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Google Code Jam" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/google-code/9c5814cd-a047-490c-bda9-75d5db226a9a%40googlegroups.com >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "Google Code Jam" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/google-code/CAHaiWHO681%2BTkbbrdVPNxxFa0n7ctRrN1Va016CmUQLynvKCcw%40mail.gmail.com > <https://groups.google.com/d/msgid/google-code/CAHaiWHO681%2BTkbbrdVPNxxFa0n7ctRrN1Va016CmUQLynvKCcw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Google Code Jam" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/google-code/CAJVC%2BwRa%3DGQ8P2io_Ln9PaanN3ZMHUaNeZ52soia-gXDWBrTLg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
