sayan_244's blog

By sayan_244, history, 6 months ago, In English

Hello everyone. I was trying to learn how GDB works and learn about debugging.

While trying to set breakpoint on main function I saw that it's not displaying the line number in decimal.

So I looked up a bit and found that one needs to include the -g flag while compiling the cpp file.

I did that and yet it doesn't show the line numbers in decimal. (Thereafter I tried to search this up but couldn't get the issue resolved)

My GDB version is 7.6.1 (probably latest for windows)

If someone can help me out with this it would be much appreciated.

UPD: Found out issue. Seems like compilation generates a separate file (a.out) and you have to run gdb on that file.

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By sayan_244, history, 9 months ago, In English

Hello guys.

I was trying the problem

The intended complexity of my solution is supposed to be $$$O(n\sqrt{n})$$$ but somehow I was repeatedly getting TLE. When I switched the concerned part where I was using + for concatenation of two strings with append it got accepted.

I went over to stackoverflow for figuring out the cause but I couldn't understand much of it besides trying the reserve keyword. I also tried using the reserve keyword for reserving space for the string but it resulted in TLE as well.

Here are my submissions:- -Using append. -Using + for concatenation.

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By sayan_244, history, 10 months ago, In English

While learning about segment tree I came across this problem:-

The task is as follows: for a given value x we have to quickly find smallest index i such that the sum of the first i elements of the array a[] is greater or equal to x (assuming that the array a[] only contains non-negative values).


The solution mentions storing prefix sums in the segment trees.

I cannot figure out how to build up a segment tree of prefix sums. Also how is it different from the range sums?

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