Added task 1

Author: javadev

.github/workflows/build.yml

@@ -0,0 +1,32 @@
+name: build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    name: check
+    runs-on: ubuntu-latest
+    steps:
+      - name: setup
+        uses: actions/setup-go@v2
+        with:
+          go-version: ^1.21
+
+      - name: checkout
+        uses: actions/checkout@v4
+
+      - name: fmt
+        run: diff -u <(echo -n) <(gofmt -d -s .)
+
+      - name: vet
+        run: go vet ./...
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v2
+
+      - name: test
+        run: go test -v -race -coverprofile=coverage.txt -covermode=atomic ./...

.github/workflows/go.yml

@@ -0,0 +1,19 @@
+all: fmt vet golangci-lint golint test
+
+check: fmt vet golangci-lint golint
+
+fmt:
+	test `go fmt ./... | wc -l` -eq 0
+
+vet:
+	go vet ./...
+
+golangci-lint:
+	golangci-lint run ./...
+
+golint:
+	test `golint ./... | grep -v 'should not use dot imports' | wc -l` -eq 0
+
+test:
+	go test -v -race -coverprofile=coverage.txt -covermode=atomic ./...
+

Makefile

@@ -0,0 +1,11 @@
+module github.com/javadev/algorithm-go
+
+go 1.21
+
+require github.com/stretchr/testify v1.8.2
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.mod

@@ -0,0 +1 @@
+# [Two Sum](https://leetcode.com/problems/two-sum/)

leetcode/0001.two-sum/README.md

@@ -0,0 +1,24 @@
+package leetcode
+
+func twoSum1(nums []int, target int) []int {
+	for i := range nums {
+		for j := range nums {
+			if i != j && (nums[i]+nums[j]) == target {
+				return []int{i, j}
+			}
+		}
+	}
+	return nil
+}
+
+func twoSum2(nums []int, target int) []int {
+	lookup := make(map[int]int)
+	for i, v := range nums {
+		j, ok := lookup[v]
+		lookup[target-v] = i
+		if ok {
+			return []int{j, i}
+		}
+	}
+	return nil
+}

leetcode/0001.two-sum/two_sum.go

@@ -0,0 +1,42 @@
+package leetcode
+
+import (
+	"reflect"
+	"testing"
+)
+
+var (
+	case1, target1, result1 = []int{2, 7, 11, 15}, 9, []int{0, 1}
+	case2, target2, result2 = []int{7, 11, 15}, 22, []int{0, 2}
+	case3, target3, result3 = []int{11, 15}, 26, []int{0, 1}
+)
+
+func TestTwoSum1(t *testing.T) {
+	if !reflect.DeepEqual(twoSum1(case1, target1), result1) {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(twoSum1(case2, target2), result2) {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(twoSum1(case3, target3), result3) {
+		t.Fail()
+	}
+	if twoSum1(nil, 0) != nil {
+		t.Fail()
+	}
+}
+
+func TestTwoSum2(t *testing.T) {
+	if !reflect.DeepEqual(twoSum2(case1, target1), result1) {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(twoSum2(case2, target2), result2) {
+		t.Fail()
+	}
+	if !reflect.DeepEqual(twoSum2(case3, target3), result3) {
+		t.Fail()
+	}
+	if twoSum2(nil, 0) != nil {
+		t.Fail()
+	}
+}