# Schrödinger's Programmer

## [LeetCode] #1732 Find the Highest Altitude (Easy)

LeetCode 第 1732 題 Find the Highest Altitude，難度 Easy

Ray

# 原始題目

There is a biker going on a road trip. The road trip consists of `n + 1` points at different altitudes.
The biker starts his trip on point 0 with altitude equal 0.

You are given an integer array `gain` of length `n` where `gain[i]` is the net gain in altitude between points `i` and `i + 1` for all (`0 <= i < n`).
Return the highest altitude of a point.

Example:

``````Input: gain = [-5,1,5,0,-7]
Output: 1
Explanation: The altitudes are [0,-5,-4,1,1,-6]. The highest is 1.

Input: gain = [-4,-3,-2,-1,4,3,2]
Output: 0
Explanation: The altitudes are [0,-4,-7,-9,-10,-6,-3,-1]. The highest is 0.
``````

# 題目分析

1. 輸入一個陣列，代表一個自行車手的海拔變化。從 0 開始騎
2. 每一個點代表和前一個點的海拔「差距」
3. 回傳最高海拔的點

# 解題過程

``````class Solution {

/**
* @param Integer[] \$gain
* @return Integer
*/
function largestAltitude(\$gain) {
\$current_altitude = 0;
\$max = 0;

foreach(\$gain as \$k => \$v) {
\$current_altitude += \$v;
if (\$current_altitude > \$max)  {
\$max = \$current_altitude;
}
}

return \$max;
}
}
``````