Any book for problem solving ?

Answer 1

"How to Solve It" by Pólya.

Answer 2

Maybe try LeetCode?🤔
https://leetcode.com
It's online code problems, much more and harder than those in SoloLearn😀

Answer 3

Visit these sites to get the link of problem solving books!!!

And you can also use websites such as: top coder, spoj.pl, codeforces etc for problem solving!!
https://www.goodreads.com/shelf/show/problem-solving-coding-computer

https://www.codingdojo.com/blog/9-best-programming-books-read-right-now-want-distinguish/