problem with code

Question

in the attached code, the problem is not evident, pls help me correct this code

https://code.sololearn.com/ckSf18BK2IlE/?ref=app

Answer 1

There are multiple issues:
1. The variable 'v' is not initialized, you should assign it an initial value (0):

int v = 0;

2. std::pow() returns a floating type value, but it looks like you are relying on integer division in your first loop condition. Casting the result to an integral value would solve this, e.g.

...; n / ( int ) pow( 10, i ); ...

3. You need to start writing digits into the array starting at ( u - 1 ), not 'u'. Either you change the index you access the array with, or the loop initialization and value calculation, e.g.

digits[ u - 1 ] = first_digit;

Answer 2

thank you very much, i did what u explained in the first two points and it worked, i could not understand your third point, anyway i dont understand how initializing v was important?