121. 买卖股票的最佳时机

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

class Solution {
public:
    int maxProfit(vector<int>& prices) {
        int ans = 0, minPrice = prices[0];
        for (int &price : prices) {
            ans = max(ans, price - minPrice);
            minPrice = min(minPrice, price);
        }
        return ans;
    }
};

1
2
3
4
5
6
7

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
        ans, min_price = 0, prices[0]
        for price in prices:
            ans = max(ans, price - min_price)
            min_price = min(min_price, price)
        return ans

 1
 2
 3
 4
 5
 6
 7
 8
 9
10

class Solution {
    fun maxProfit(prices: IntArray): Int {
        var (ans, minPrice) = 0 to prices[0]
        for (price in prices) {
            ans = maxOf(ans, price - minPrice)
            minPrice = minOf(minPrice, price)
        }
        return ans
    }
}