HackerRank Stryker Code Sprint Grind (V) - The Hidden Message - 70%

Sept. 18, 2016

Problem statement

Julia's C# solution is here.

Here is the timeline Julia worked on the problem solving:

Section 1:
 /* 7:08pm - start to read the problem statement
     *
     * 7:47pm start to write down her approach
     * start position is increasing
     * How to find word match?
     *
     * Time complexity -
     * Data structure
     * Space complexity:
     *
     * 7:55pm start to code
     *
     * 10:04pm start to conduct testing
     */

 Section 2: 
Copy the code from previous practice - substring search, using Boyer algorithm to speed up, avoid timeout issues. 
/*
         * 8:24pm
         * copy code from blog:
         * http://juliachencoding.blogspot.ca/2016/04/hackerrank-string-function-calculation_10.html
         *
         * 8:36 prepare to exit the function
         */
        private static bool findUsingBoyerAlgo(string substring, string s, ref int start)

Section 3:
/*
         * 9:02pm - start to code
         * 9:43pm - still work on the calculation of cost
         * - try to think about how many chars to be removed - second step
         * 9:57pm use brute force solution first
         */
        public static string calculateCost(IList<Match> data,
            string message
            )

Section 4:
 /*
     * 10:19pm
     * Summary of submission:
     * 40.80/60
     * Wrong answer for test case: 11, 15
     * Try to fix the bug
     */

Summary:
1. 40 minutes to read the problem statement
2. 2 hours coding - including eating a dinner - 20 minutes

55 minutes to work on calculation of cost, looked into interval algorithm, and then, figured out using brute force solution instead.

2. 10:04pm testing

Score 40.80/ 60 

Decided to give up bug fix, and then, moved on next question.

Study C# submission - 60 out of 60
1. Use Trie

2. C#: use dynamic programming.

Related to Leetcode 72: "Edit Distance"

3. Study the blog: Levenshtein Distance wiki

4. Study Java 8 solution - use Rabin Karp algorithm search class, DP

5. C++ code - Learn from the best, competitive programmer

6. C++ - KMP algorithm, DP

7. The programmer - 5 Gold - rank 32/1700
a Googler, a blog.

Talk about Google code review - in Chinese, link is here.