Google Software Development Engineer SDE interview questions

Before we begin: ONLY DSA Questions were asked. Not a single question related to OS, DBMS, CNS, OOP, System design or even Resume was asked. So now you know what to focus on. Round-1 (Online Coding Test, Platform: HackerEarth): All students were eligible for Round-1. (No constraints based on CPI or active backlogs) Q1 (30 points): You are given a string S of length N consisting of digits from ‘0’ to ‘9’. You need to partition the string in ‘K’ substrings such that each substring starts with an even digit and ends with an odd digit. Each substring must be of Length at least equal to ‘M’. Determine the total number of ways in which you can partition the string into ‘K’ substrings. Give answer modulo 1e9+7. Sample: N=9, M=2, K=3, S=’454569421′

It is a couple of hard technical rounds mostly you are evaluated on how you think not if you are able to solve the question for example if you brute force and give an answer it wont work