[#3516] feat(go): add golang solution

problems/3516-find-closest-person/go/go.mod

@@ -0,0 +1,3 @@
+module leetcode-3516
+
+go 1.18

problems/3516-find-closest-person/go/main.go

@@ -0,0 +1,71 @@
+// LeetCode 3516: Find Closest Person
+// 難度: Easy
+// 日期: 2025-09-04
+
+package main
+
+import "fmt"
+
+// TODO: 實作解法
+func findClosest(x, y, z int) int {
+    distanceX := abs(x - z)
+    distanceY := abs(y - z)
+
+    if distanceX == distanceY{
+        return 0
+    }else if distanceX > distanceY{
+        return 2
+    }else{
+        return 1
+    }
+}
+
+func abs(n int) int{
+    if n < 0 {
+        return -n
+    }
+    return n
+}
+
+func main() {
+    testCase1()
+    testCase2()
+    testCase3()
+}
+
+// 基本測試案例 - Example 1
+func testCase1() {
+    // Input: x = 2, y = 7, z = 4
+    // Expected: 1 (Person 1 距離較近: |2-4| = 2 < |7-4| = 3)
+    actual := findClosest(2, 7, 4)
+    expected := 1
+    fmt.Printf("Test 1: Input(2, 7, 4) Expected: %d, Actual: %d, Result: %s\n", 
+        expected, actual, getResult(actual == expected))
+}
+
+// 基本測試案例 - Example 2
+func testCase2() {
+    // Input: x = 2, y = 5, z = 6
+    // Expected: 2 (Person 2 距離較近: |5-6| = 1 < |2-6| = 4)
+    actual := findClosest(2, 5, 6)
+    expected := 2
+    fmt.Printf("Test 2: Input(2, 5, 6) Expected: %d, Actual: %d, Result: %s\n", 
+        expected, actual, getResult(actual == expected))
+}
+
+// 基本測試案例 - Example 3
+func testCase3() {
+    // Input: x = 1, y = 5, z = 3
+    // Expected: 0 (距離相等: |1-3| = 2 = |5-3| = 2)
+    actual := findClosest(1, 5, 3)
+    expected := 0
+    fmt.Printf("Test 3: Input(1, 5, 3) Expected: %d, Actual: %d, Result: %s\n", 
+        expected, actual, getResult(actual == expected))
+}
+
+func getResult(pass bool) string {
+    if pass {
+        return "PASS"
+    }
+    return "FAIL"
+}