ARTS 035
Algorihm
11. Container With Most Water
Difficulty: Medium
Given n non-negative integers a1, a2, …, an , where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.
Note: You may not slant the container and n is at least 2.
The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7]. In this case, the max area of water (blue section) the container can contain is 49.
Example:
Input: [1,8,6,2,5,4,8,3,7]
Output: 49
Solution
Language: Swift
最容易想出来的解决方案应该就是两层循环，不出意外会超时，一般两层循环的在leetcode都会超时。
class Solution {
func maxArea(_ height: [Int]) -> Int {
var maxArea = 0
for i in 0..<height.count {
let left = height[i]
for j in (i + 1)..<height.count {
let right = height[j]
let rightIndex = j
let tem = min(left, right) * (rightIndex - i)
maxArea = max(maxArea, tem)
}
}
return maxArea
}
}
看了别人的提示后，发现了O(N)时间复杂度的解决办法，从数组的两端向中间移动。具体解决方案如下：
class Solution {
func maxArea(_ height: [Int]) -> Int {
var maxArea = 0
var left = 0
var right = height.count - 1
var leftValue = 0
var rightValue = 0
while left < right {
leftValue = height[left]
rightValue = height[right]
maxArea = max(maxArea, min(leftValue, rightValue) * (right - left))
if leftValue > rightValue {
right -= 1
}
else{
left += 1
}
}
return maxArea
}
}
Review
程序员如何和HR谈Offer： https://dandan2009.github.io/2019/12/10/job-negotiation-for-programmers-the-basic-principles/
Tips
-
Tips1: zsh alias 怎么加参数？
我们知道alias可以简化命令，比如下面
alias ios='cd /Users/dan/Documents/wanan/ios/iv && pod install --no-repo-update && open iv.xcworkspace'在终端输入
ios就可以执行三条命令。
那么怎么alias 命令怎么带参数呢，答案就是用函数。
deletefile() { rm -rf $1 echo rm -rf $1 } alias dele=deletefile在终端输入 dele 2.txt, 就会执行
rm -rf 2.txt echo rm -rf 2.txt -
Tips2: iOS价格显示问题，用NSDecimalNumber 处理价格
@property(nonatomic, strong) NSDecimalNumber* price;//< 单位：元接口返回是NSNumber类型，有些数字解析会有问题，比如实际数据是9.8，但是AFN返回的是9.800000000000001，导致显示有问题，
解决办法，重写set方法，用NSDecimalNumberHandler处理一下。
- (void)setPrice:(NSDecimalNumber *)price{ NSDecimalNumberHandler *handler = [NSDecimalNumberHandler decimalNumberHandlerWithRoundingMode:NSRoundDown scale:2 raiseOnExactness:NO raiseOnOverflow:NO raiseOnUnderflow:NO raiseOnDivideByZero:NO]; _price = [price decimalNumberByRoundingAccordingToBehavior:handler]; }; RoundingMode： NSRoundDown只舍不入 scale ： 2 保留两位小数 -
Tips3: Mac ssh-key如何配置多个
在 ~/.ssh 目录下新建config文件或者编辑config文件
config文件内容如下：
# github 的ssh-key Host github.com User xxxx@gmail.com PreferredAuthentications publickey IdentityFile ~/.ssh/github # coding.net的ssh-key Host gitlab.coding.net User xxxx@qq.com PreferredAuthentications publickey IdentityFile ~/.ssh/id_rsa
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