Say you have an array for which the ith element is the price of a given stock on day i.
Design an algorithm to find the maximum profit. You may complete as many transactions as you like (i.e., buy one and sell one share of the stock multiple times).
Note: You may not engage in multiple transactions at the same time (i.e., you must sell the stock before you buy again).
Example 1:
Input: [7,1,5,3,6,4]
Output: 7
Explanation: Buy on day 2 (price = 1) and sell on day 3 (price = 5), profit = 5-1 = 4.
Then buy on day 4 (price = 3) and sell on day 5 (price = 6), profit = 6-3 = 3.
Example 2:
Input: [1,2,3,4,5]
Output: 4
Explanation: Buy on day 1 (price = 1) and sell on day 5 (price = 5), profit = 5-1 = 4.
Note that you cannot buy on day 1, buy on day 2 and sell them later, as you are
engaging multiple transactions at the same time. You must sell before buying again.
Example 3:
Input: [7,6,4,3,1]
Output: 0
Explanation: In this case, no transaction is done, i.e. max profit = 0.
Tags: Array, Greedy
题意是给出一个数组代表每天的股票金额，在每天只能买或卖的情况下求出收益最高值，
这...，这也太简单了吧，把所有相邻递增的值都加起来即可。
实际上为greedy 贪婪算法，分析情况：
1、如果为一直递增，那么相当于最大的减去最小的，比如[1, 4, 5], (4 - 1) + (5 - 4) = 5 - 1;
2、如果有波峰，波谷，那么递增的则累加，比如[1, 4, 2, 8], (4 -1) + (8 - 2)
class Solution {
func maxProfit(_ prices: [Int]) -> Int {
var maxProfitInt = 0
if prices.count < 1 {
return maxProfitInt
}
for i in 1..<prices.count {
if prices[i] > prices[i - 1] {
maxProfitInt += (prices[i] - prices[i - 1])
}
}
return maxProfitInt
}
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