refactor: move LeetCode solutions to per-problem package directories (#3)

* refactor: move each LeetCode solution into per-problem package dirs

* chore: align docs, validation, and CI with per-problem layout

* fix: use keyed struct literals for util types

* fix: key TreeNode literals in tests for govet

Author: eselyavka

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version-file: localhost/leetcode/go.mod
+          go-version: '1.26.x'
           cache-dependency-path: |
             localhost/leetcode/go.sum
 
@@ -42,7 +42,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version-file: localhost/leetcode/go.mod
+          go-version: '1.26.x'
           cache-dependency-path: |
             localhost/leetcode/go.sum
 

README.md

@@ -6,27 +6,26 @@ Repository for practicing LeetCode problems in Go with standardized structure, C
 
 - `localhost/leetcode/`: Go module root.
 - `localhost/leetcode/problems/<0001-0300>/`: range folders (300 problems each).
-- `localhost/leetcode/problems/<range>/solution_<id>.go`: solution implementation.
-- `localhost/leetcode/problems/<range>/solution_<id>_test.go`: solution tests.
-- `localhost/leetcode/constants.go`: canonical shared constants file.
-- `localhost/leetcode/leetcode_shared_libs.go`: canonical shared helper functions.
-- `localhost/leetcode/problems/<range>/constants.go`: symlink to `../../constants.go`.
-- `localhost/leetcode/problems/<range>/leetcode_shared_libs.go`: symlink to `../../leetcode_shared_libs.go`.
-- `localhost/leetcode/problems/<range>/types.go`: range-local compatibility types.
+- `localhost/leetcode/problems/<range>/p<id>/solution_<id>.go`: solution implementation.
+- `localhost/leetcode/problems/<range>/p<id>/solution_<id>_test.go`: solution tests.
+- `localhost/leetcode/util/constants.go`: shared constants.
+- `localhost/leetcode/util/helpers.go`: shared helper functions.
+- `localhost/leetcode/util/types.go`: shared types.
 - `.github/workflows/ci.yml`: CI pipeline.
 - `scripts/new_solution.sh`: Creates standardized solution stubs.
-- `scripts/validate_solutions.sh`: Validates layout, naming, package conventions, and shared-file symlinks.
+- `scripts/validate_solutions.sh`: Validates per-problem layout and package conventions.
 - `.pre-commit-config.yaml`: Local pre-commit checks.
 
 ## Conventions
 
 - Go version: `1.26` (`go.mod` + `go.work`).
-- Each solution lives in a range folder:
-  - `localhost/leetcode/problems/<range>/solution_<problem_id>.go`
-- Each test lives alongside the solution:
-  - `localhost/leetcode/problems/<range>/solution_<problem_id>_test.go`
-- File package must be `solutions`.
-- Shared constants/helpers are single-source at module root and symlinked into each range folder.
+- Each solution lives in:
+  - `localhost/leetcode/problems/<range>/p<problem_id>/solution_<problem_id>.go`
+- Each test lives alongside the solution in the same `p<problem_id>` directory.
+- Package name must match the problem directory:
+  - directory `p382` uses `package p382`
+- Shared helpers/types/constants live under:
+  - `localhost/leetcode/util`
 
 ## Local Commands
 
@@ -72,6 +71,6 @@ For this repo, "CD" is continuous delivery of quality gates to `main` (no deploy
 
 ## Workflow Notes
 
-- CI uses Go from `localhost/leetcode/go.mod` (currently `1.26`).
+- CI pins Go to `1.26.x` in `.github/workflows/ci.yml`.
 - Lint workflow uses `golangci-lint-action@v9` with `golangci-lint v2`.
-- `scripts/validate_solutions.sh` supports both `rg` and `grep` so it works on runners without `ripgrep`.
+- `scripts/validate_solutions.sh` supports both `rg` and `grep`, so it works on runners without `ripgrep`.

localhost/leetcode/problems/0001-0300/constants.go

@@ -0,0 +1,16 @@
+package p1
+
+// twoSum_1 returns indices of the two numbers such that they add up to target.
+func twoSum_1(nums []int, target int) []int {
+	result := make([]int, 0, 2)
+	seenByValue := make(map[int]int, len(nums))
+
+	for i, num := range nums {
+		if j, ok := seenByValue[target-num]; ok {
+			result = append(result, j, i)
+		}
+		seenByValue[num] = i
+	}
+
+	return result
+}

localhost/leetcode/problems/0001-0300/leetcode_shared_libs.go

@@ -0,0 +1,11 @@
+package p1
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSolution1(t *testing.T) {
+	assert.Equal(t, []int{0, 1}, twoSum_1([]int{2, 7, 11, 15}, 9), "Solution1")
+}

localhost/leetcode/problems/0001-0300/p1/solution_1.go

@@ -1,6 +1,8 @@
-package solutions
+package p100
 
-func isSameTree(p *TreeNode, q *TreeNode) bool {
+import "localhost/leetcode/util"
+
+func isSameTree(p *util.TreeNode, q *util.TreeNode) bool {
 	if p == nil && q == nil {
 		return true
 	}

localhost/leetcode/problems/0001-0300/p1/solution_1_test.go

@@ -0,0 +1,31 @@
+package p100
+
+import (
+	"github.com/stretchr/testify/assert"
+	"localhost/leetcode/util"
+	"sort"
+	"strings"
+	"testing"
+)
+
+var (
+	_ = sort.Strings
+	_ = strings.Join
+)
+
+func TestSolution100(t *testing.T) {
+	assert := assert.New(t)
+
+	root1 := util.TreeNode{Val: 1, Left: nil, Right: nil}
+	root1.Left = &util.TreeNode{Val: 2, Left: nil, Right: nil}
+	root1.Right = &util.TreeNode{Val: 3, Left: nil, Right: nil}
+
+	root2 := util.TreeNode{Val: 1, Left: nil, Right: nil}
+	root2.Left = &util.TreeNode{Val: 2, Left: nil, Right: nil}
+	root2.Right = &util.TreeNode{Val: 3, Left: nil, Right: nil}
+
+	actual := isSameTree(&root1, &root2)
+
+	assert.True(actual, "Solution100")
+
+}

…tcode/problems/0001-0300/solution_100.go …/problems/0001-0300/p100/solution_100.golocalhost/leetcode/problems/0001-0300/solution_100.go renamed to localhost/leetcode/problems/0001-0300/p100/solution_100.go localhost/leetcode/problems/0001-0300/solution_100.go renamed to localhost/leetcode/problems/0001-0300/p100/solution_100.go

@@ -1,11 +1,13 @@
-package solutions
+package p102
 
-func levelOrder(root *TreeNode) [][]int {
+import "localhost/leetcode/util"
+
+func levelOrder(root *util.TreeNode) [][]int {
 	if root == nil {
 		return [][]int{}
 	}
 
-	q := make([]*TreeNode, 0)
+	q := make([]*util.TreeNode, 0)
 	q = append(q, root)
 
 	ans := make([][]int, 0)

localhost/leetcode/problems/0001-0300/p100/solution_100_test.go

@@ -0,0 +1,32 @@
+package p102
+
+import (
+	"github.com/stretchr/testify/assert"
+	"localhost/leetcode/util"
+	"sort"
+	"strings"
+	"testing"
+)
+
+var (
+	_ = sort.Strings
+	_ = strings.Join
+)
+
+func TestSolution102(t *testing.T) {
+	assert := assert.New(t)
+
+	root := util.TreeNode{Val: 6, Left: nil, Right: nil}
+	root.Left = &util.TreeNode{Val: 2, Left: nil, Right: nil}
+	root.Left.Left = &util.TreeNode{Val: 0, Left: nil, Right: nil}
+	root.Left.Right = &util.TreeNode{Val: 4, Left: nil, Right: nil}
+	root.Left.Right.Left = &util.TreeNode{Val: 3, Left: nil, Right: nil}
+	root.Left.Right.Right = &util.TreeNode{Val: 5, Left: nil, Right: nil}
+	root.Right = &util.TreeNode{Val: 8, Left: nil, Right: nil}
+	root.Right.Left = &util.TreeNode{Val: 7, Left: nil, Right: nil}
+	root.Right.Right = &util.TreeNode{Val: 9, Left: nil, Right: nil}
+
+	actual := levelOrder(&root)
+
+	assert.Equal([][]int{{6}, {2, 8}, {0, 4, 7, 9}, {3, 5}}, actual, "Solution102")
+}