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121.Best Time to Buy and Sell Stock
tags: Easy,Array,DP
121. Best Time to Buy and Sell Stock
題目描述
You are given an array prices where prices[i] is the price of a given stock on the ith day.
You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.
Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.
範例
Example 1:
Input: prices = [7,1,5,3,6,4]
Output: 5
Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
Example 2:
Input: prices = [7,6,4,3,1]
Output: 0
Explanation: In this case, no transactions are done and the max profit = 0.
Constraints:
- 1 <=
prices.length<= 105 - 0 <=
prices[i]<= 104
解答
Javascript
function maxProfit(prices) {
let max = 0;
let minPrice = prices[0];
for (let i = 1; i < prices.length; i++) {
if (prices[i] < minPrice) {
minPrice = prices[i];
}
max = Math.max(max, prices[i] - minPrice);
}
return max;
}
Marsgoat Dec 23, 2022
C++
class Solution {
public:
int maxProfit(vector<int>& prices) {
int lower = INT_MAX, ans = 0;
for (auto price : prices) {
lower = min(lower, price);
ans = max(ans, price - lower);
}
return ans;
}
};
Yen-Chi ChenFri, Dec 23, 2022
Python
class Solution:
def maxProfit(self, prices: List[int]) -> int:
lower, ans = math.inf, 0
for price in prices:
lower = min(lower, price)
ans = max(ans, price - lower)
return ans
Yen-Chi ChenFri, Dec 23, 2022
