# [3516] Find Closest Person

## 題目資訊
- **難度**: Easy
- **標籤**: Math
- **題目連結**: [LeetCode](https://leetcode.com/problems/find-closest-person/)
- **練習日期**: 2025-09-04

## 題目描述
You are given three integers `x`, `y`, and `z`, representing the positions of three people on a number line:

`x` is the position of Person 1.
`y` is the position of Person 2.
`z` is the position of Person 3, who does **not** move.
Both Person 1 and Person 2 move toward Person 3 at the same speed.

Determine which person reaches Person 3 first:

Return 1 if Person 1 arrives first.
Return 2 if Person 2 arrives first.
Return 0 if both arrive at the same time.
Return the result accordingly.

## 解題思路

### 初步分析
- 這題主要考察什麼概念？
   距離計算和比較。使用絕對值計算兩點間距離
- 有什麼關鍵限制條件？
   比較兩個距離的大小關係
- 預期時間/空間複雜度？
   時間 O(1)，空間 O(1) - 只需要常數時間的計算

### 解法概述
**解法**: 
   - 思路：
      分別計算 Person 1 和 Person 2 到 Person 3 的距離，直接比較大小
   - 時間複雜度：O(1)
   - 空間複雜度：O(1)

## 測試案例

### 範例輸入輸出
```
Input: x = 2, y = 7, z = 4
Output: 1
Explanation: 
- Person 1 is at position 2 and can reach Person 3 (at position 4) in 2 steps.
- Person 2 is at position 7 and can reach Person 3 in 3 steps.
Since Person 1 reaches Person 3 first, the output is 1.
```

### 邊界情況
`1 <= x, y, z <= 100`

## 學習筆記

### 今天學到什麼？
- 稍微練習了一下go func

### 遇到的困難
- 無

### 改善方向
- 無

### 相關題目

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**總結**: 今天這題考弱智?