Hi, I am sending my greetings to you, I find problem D in the last round is really hard and I can't reach for a solution, I have read the tutorial but still don't get the solution, for some reason this situation makes me feel annoyed I don't feel good until I get the solution and this situation happens a lot with me, I guess you might know exactly what I am talking about, so if you solved the problem I would appreciate if you share your solution, thanks in advance.

How to find number of values x which achieve GCD(n, x) = 1
n is constant
x <= m
m can be bigger than n
the related problem to this question that I am trying to solve:

https://mirror.codeforces.com/contest/1750/problem/D

If I have a Program.exe that takes input and print it.
If I want to run this program from the cmd I will go to its directory and write Program.exe (enter).
And what is going to happen a new line and waiting for the input.
But what if I want to give the input at the same line like that :

c:\Users\abc> Program.exe input
and that's it the program doesn't ask for input(as I gave it at the same line when I invoked the program) and print the output and terminate

I am working with c++.

AT this problem https://mirror.codeforces.com/gym/102470/problem/A (short statment below)
after three days of coding to avoid runtime error I get TLE on a binary search solution can someone explain what is wrong with my solution

the short statement : You are given set of points (x,y) find point on (y = 0) which all point can go to this point in minimum time and all have the same speed which is one meter per second

my code : https://mirror.codeforces.com/contest/1445/submission/98270485 (the code has comments :)

I really want to know how to solve this problem :

You are given two positive integers d and s. Find minimal positive integer n which is divisible by d and has sum of digits equal to s.

the link : https://mirror.codeforces.com/contest/1070/problem/A

If I am calling too many functions which is more than allowed in the memory limit I will get run time error or memory limit exceeded ? like in this code https://mirror.codeforces.com/contest/1067/submission/85187079

UPD If I am calling too many functions which is more than the stack size I will get run time error or memory limit exceeded ?

Can someone provide a tutorial on how to use prefix sum with dynamic programming ?

Given a string consist just of the letter 'u' ,if we can consider every two adjacent 'u' -->' w' and every u can be used only once in how many ways the string can appear ?

example : uuu can be uuu or wu or u w so the answer is 3 .

I am asking this question because at the last contest I was trying to solve this problem https://mirror.codeforces.com/contest/1245/problem/C and I claim the solution is every continuous 'u' or 'n' I save in how many ways it can appear in a vector and then multiply all the numbers and this is the answer .