122.MaxProfit.cs

// 122. Best Time to Buy and Sell Stock II

// You are given an integer array prices where prices[i] is the price of a given stock on the ith day.

// On each day, you may decide to buy and/or sell the stock. You can only hold at most one share of the stock at any time. 
// However, you can buy it then immediately sell it on the same day.

// Find and return the maximum profit you can achieve.

// Example 1:
// Input: prices = [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.
// Total profit is 4 + 3 = 7.
// Example 2:
// Input: prices = [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.
// Total profit is 4.
// Example 3:
// Input: prices = [7,6,4,3,1]
// Output: 0
// Explanation: There is no way to make a positive profit, so we never buy the stock to achieve the maximum profit of 0.

public class Solution {
    public int MaxProfit(int[] prices) {
        int profit = 0;
        for(int i=0;i<prices.Length-1;i++){
            //Since we can buy it then immediately sell it on the same day, We can sell evertime value increses and than buy on same day.
            if(prices[i]<prices[i+1])
                profit += prices[i+1] - prices[i];
        }
        return profit;
    }
}