One day after I submitted my resume on their site, I received a link from HR to a testing site with two tasks to complete. I did one of them; the second one, regarding DP, was not completely solved by me.

I did not get any feedback from them after that.

Task 1. You are given a string containing just numbers and mathematical operators + and *.

You have to read from the string characters one by one. If it is a digit, then push it onto the stack. If it is an operator, pop 2 elements from the stack, apply the operator to those elements, and push the result onto the stack. If there are not enough elements in the stack, or no operator to apply, return -1.

For example: "12+47" You have to calculate a result like this: 1 -> push onto stack 2 -> push onto stack

• -> pop 1 from stack, pop 2 from stack, perform 1 + 2, and push 3 onto stack 4 -> push onto stack

• -> pop 4, pop 3, multiply them, and put 12 onto stack. 7 -> push onto stack
• -> push 7 and 12 from stack and multiply them. Return 84.

Task 2. It was about dynamic programming/greedy algorithms. 1 day ticket costs 2 dollars. 7 day ticket costs 7 dollars (valid for a sequence of 7 days). One month ticket costs 25. You are given a list of increasing dates you gonna travel. You have to return the minimum possible amount of money you spend on tickets. For example: 1, 2, 3, 4, 5, 11, 12, 25. Return 13.