121. Best Time to Buy and Sell Stock Leetcode Solution

class Solution {
public:
    int maxProfit(vector< int>& prices) {
        int n=prices.size();
        int l[n],r[n];
        l[0]=prices[0];
        r[n-1]=prices[n-1];
        
        for(int i=1;i< n;i++){
            l[i]=min(l[i-1],prices[i]);
        }

        for(int i=n-2;i>=0;i--){
            r[i]=max(r[i+1],prices[i]);
        }

        int maxProfit=0;
        for(int i=0;i< n;i++){
            maxProfit=max(maxProfit,r[i]-l[i]);
        }

        return maxProfit;
    }
};

class Solution {
    public int maxProfit(int[] prices) {
        int min_price = prices[0];
        int maxprof = 0;

        for(int i=1;i< prices.length;i++){
            maxprof = Math.max(maxprof,prices[i]-min_price);
            min_price = Math.min(prices[i],min_price);
        }

        return maxprof;
    }
}

class Solution:
    def maxProfit(self, prices: List[int]) -> int:
        min_price = prices[0]
        max_profit = 0
        
        for price in prices[1:]:
            max_profit = max(max_profit, price - min_price)
            min_price = min(min_price, price)
            
        return max_profit