Example comments for the rest of the problems

Author: spring1843

strings/longest_substring_test.go

@@ -7,7 +7,15 @@ TestLongestSubstrings tests solution(s) with the following signature and problem
 
 	func LongestSubstringOfTwoChars(input string) string
 
-Given a string like "aabbc" return the longest substring of two unique characters like "aabb".
+Given a string return the longest substring of two unique characters.
+
+For example given "aabbc", return "aabb" because it's the longest substring that has two unique
+characters "a" and "b".
+
+Other substrings of "aabc" include:
+
+* "aabbc", contains more than 2 unique characters.
+* "bbc", shorter than "aabb".
 */
 func TestLongestSubstrings(t *testing.T) {
 	tests := []struct {
@@ -21,7 +29,7 @@ func TestLongestSubstrings(t *testing.T) {
 		{"aabbc", "aabb"},
 		{"ada", "ada"},
 		{"dafff", "afff"},
-		{"assdeeeddfffha", "deeedd"},
+		{"abbdeeeddfffha", "deeedd"},
 	}
 
 	for i, test := range tests {

strings/look_and_tell_test.go

@@ -7,8 +7,27 @@ TestFindDuplicate tests solution(s) with the following signature and problem des
 
 	func LookAndTell(depth int) []string
 
-Given a depth, return the output of look and tell an algorithm where each line reads the
-last line. For example "1" is read as "11" (one one), and "11" is read as "21" (two ones).
+Given a positive integer n, return the output of the Look and Tell algorithm until the nth depth.
+
+The Look and Tell algorithm starts by outputting 1 at first level, then at each subsequent level
+it reads the previous line by counting the number of times a digit is repeated and then writes
+the count and the digit.
+
+For example given 4, return:
+
+1
+11
+21
+1211
+
+Which reads:
+one
+one one
+two ones
+one two one one.
+
+The third output (two ones) reads the level before it which is 11. Two ones means repeat
+1 two times i.e. 11.
 */
 func TestFindDuplicate(t *testing.T) {
 	tests := []struct {

strings/number_in_english_test.go

@@ -7,8 +7,12 @@ TestReadNumberInEnglish tests solution(s) with the following signature and probl
 
 	func NumberInEnglish(num int) string
 
-Given a number like 34, return how the number  would be read in English e.g. (Thirty Four) for
-integers smaller than one Trillion.
+Given n a positive integer smaller than a Trillion, return the number in English words.
+
+For example given 0, return "Zero".
+For example given 34, return "Thirty Four".
+For example given 10, return "Ten".
+For example given 900000000001, return "Nine Hundred Billion One".
 */
 func TestReadNumberInEnglish(t *testing.T) {
 	tests := []struct {
@@ -18,10 +22,12 @@ func TestReadNumberInEnglish(t *testing.T) {
 		{0, "Zero"},
 		{1, "One"},
 		{2, "Two"},
+		{10, "Ten"},
 		{34, "Thirty Four"},
 		{123456789, "One Hundred Twenty Three Million Four Hundred Fifty Six Thousand Seven Hundred Eighty Nine"},
 		{1000000000, "One Billion"},
 		{100000000000, "One Hundred Billion"},
+		{900000000001, "Nine Hundred Billion One"},
 	}
 
 	for i, test := range tests {

strings/reverse_vowels_test.go

@@ -7,7 +7,11 @@ TestReverseVowels tests solution(s) with the following signature and problem des
 
 	func ReverseVowels(str string) (string, error)
 
-Given a string e.g. "coat", reverse the order in which vowels appear e.g. "caot".
+Given a string, return the same string while reversing the vowels {"a", "e", "i", "o", "u"}
+appear in it.
+
+For example given "coat", return "caot", because the vowels are "o" and "a" and their positions
+are reversed.
 */
 func TestReverseVowels(t *testing.T) {
 	tests := []struct {

strings/roman_numerals_test.go

@@ -7,7 +7,24 @@ TestIntToRoman tests solution(s) with the following signature and problem descri
 
 	func IntToRoman(input int) string
 
-Given a positive integer like 1917 return the Roman numeral like MCMXVII.
+Given a positive integer like return the equivalent inRoman numerals:
+
+For example:
+
+* Given 1, return I
+* Given 4, return IV
+* Given 5, return V
+* Given 9, return IX
+* Given 10, return X
+* Given 40, return XL
+* Given 50, return L
+* Given 90, return XC
+* Given 100, return C
+* Given 400, return CD
+* Given 500, return D
+* Given 900, return CM
+* Given 1000, return M
+* Given 1917, return MCMXVII.
 */
 func TestIntToRoman(t *testing.T) {
 	tests := []struct {