feat: add romanToInteger solution

.golangci.yaml

@@ -0,0 +1,29 @@
+linters:
+  enable:
+    - errorlint
+    #- godot
+    - goimports
+    - misspell
+    - nolintlint
+    - predeclared
+    - testifylint
+    - unconvert
+    - durationcheck
+    - exportloopref
+    - nilerr
+    - whitespace
+    - unparam
+    - tagalign
+    - stylecheck
+    - gosec
+    #- gofumpt
+    #- perfsprint
+    # - nestif
+    # - noctx
+    # - prealloc
+    # - depguard
+    # - revive
+    # - gocritic
+    # - wastedassign
+    # - goconst
+    # - gomnd

LeetCode/problem001_TwoSum.go

@@ -6,7 +6,7 @@ package leetcode
 
 // Time complexity:  O(n^2)
 // Space complexity: O(1)
-func TwoSumBruteForce(nums []int, target int) []int {
+func twoSumBruteForce(nums []int, target int) []int {
 	for i := 0; i < len(nums); i++ {
 		for j := i + 1; j < len(nums); j++ {
 			if nums[i]+nums[j] == target {
@@ -19,7 +19,7 @@ func TwoSumBruteForce(nums []int, target int) []int {
 
 // Time complexity:  O(n)
 // Space complexity: O(n)
-func TwoSumHashMap(nums []int, target int) []int {
+func twoSumHashMap(nums []int, target int) []int {
 	hashMap := make(map[int]int)
 	for i, num := range nums {
 		complement := target - num

LeetCode/problem001_TwoSum_test.go

@@ -5,22 +5,22 @@ import (
 	"testing"
 )
 
-var tests = []struct {
-	name   string
-	nums   []int
-	target int
-	output []int
-}{
-	{"case1", []int{2, 7, 11, 15}, 9, []int{0, 1}},
-	{"case2", []int{2, 1, 5, 3}, 4, []int{1, 3}},
-	{"case3", []int{3, 2, 4}, 6, []int{1, 2}},
-	{"case4", []int{3, 3}, 6, []int{0, 1}},
-}
-
 func TestTwoSumBruteForce(t *testing.T) {
+	var tests = []struct {
+		name   string
+		nums   []int
+		target int
+		output []int
+	}{
+		{"case1", []int{2, 7, 11, 15}, 9, []int{0, 1}},
+		{"case2", []int{2, 1, 5, 3}, 4, []int{1, 3}},
+		{"case3", []int{3, 2, 4}, 6, []int{1, 2}},
+		{"case4", []int{3, 3}, 6, []int{0, 1}},
+	}
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			result := TwoSumBruteForce(tt.nums, tt.target)
+			result := twoSumBruteForce(tt.nums, tt.target)
 			if !reflect.DeepEqual(result, tt.output) {
 				t.Errorf("TwoSumBruteForce(%v, %v) = %v; want %v", tt.nums, tt.target, result, tt.output)
 			}
@@ -29,9 +29,21 @@ func TestTwoSumBruteForce(t *testing.T) {
 }
 
 func TestTwoSumHashMap(t *testing.T) {
+	var tests = []struct {
+		name   string
+		nums   []int
+		target int
+		output []int
+	}{
+		{"case1", []int{2, 7, 11, 15}, 9, []int{0, 1}},
+		{"case2", []int{2, 1, 5, 3}, 4, []int{1, 3}},
+		{"case3", []int{3, 2, 4}, 6, []int{1, 2}},
+		{"case4", []int{3, 3}, 6, []int{0, 1}},
+	}
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			result := TwoSumHashMap(tt.nums, tt.target)
+			result := twoSumHashMap(tt.nums, tt.target)
 			if !reflect.DeepEqual(result, tt.output) {
 				t.Errorf("TwoSumHashMap(%v, %v) = %v; want %v", tt.nums, tt.target, result, tt.output)
 			}

LeetCode/problem009_PalindromeNumber.go

@@ -1,10 +1,15 @@
-/* Problem 9. Palindrome Number */
+/*
+Problem 9. Palindrome Number
+*/
+
 package leetcode
 
 import (
 	"math"
 )
 
+// Time complexity:  O(log10​(n))
+// Space complexity: O(1)
 func isPalindrome(x int) bool {
 	// Negative numbers are not palindromes
 	if x < 0 {

LeetCode/problem013_RomanToInteger.go

@@ -0,0 +1,31 @@
+/*
+13. Roman to Integer
+*/
+
+package leetcode
+
+// Time complexity:  O(n)
+// Space complexity: O(1)
+func romanToInteger(s string) int {
+	roman := map[byte]int{
+		'I': 1,
+		'V': 5,
+		'X': 10,
+		'L': 50,
+		'C': 100,
+		'D': 500,
+		'M': 1000,
+	}
+	n := len(s)
+	total := 0
+
+	for i := 0; i < n; i++ {
+		if i+1 < n && roman[s[i]] < roman[s[i+1]] {
+			total -= roman[s[i]]
+		} else {
+			total += roman[s[i]]
+		}
+	}
+
+	return total
+}

LeetCode/problem013_RomanToInteger_test.go

@@ -0,0 +1,28 @@
+package leetcode
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestRomanToInteger(t *testing.T) {
+	var tests = []struct {
+		name   string
+		input  string
+		output int
+	}{
+		{"case1", "III", 3},
+		{"case2", "LVIII", 58},
+		{"case3", "MCMXCIV", 1994},
+		{"case4", "CMXCVIII", 998},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := romanToInteger(tt.input)
+			if !reflect.DeepEqual(result, tt.output) {
+				t.Errorf("romanToInteger(%v) = %v; want %v", tt.input, result, tt.output)
+			}
+		})
+	}
+}