LeetCode/122. BestTimeToBuyAndSellStock2

Link

• https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/

Summary

Since I’ve already solved the first one, solving second one was easy.

Solutions

My Solution

Despite I’ve already know the last best solution, I’ve tried with my way which is more intuitive to me.

public int MaxProfit(int[] prices)
{
    var previousVal = int.MaxValue;
    var minVal = int.MaxValue;
    var maxVal = int.MinValue;
    var result = 0;

    for (int i = 0; i < prices.Length; i++)
    {
        if (prices[i] < previousVal)
        {
            minVal = Math.Min(minVal, prices[i]);
            maxVal = int.MinValue;
        }
        else
        {
            maxVal = Math.Max(maxVal, prices[i]);
            result += minVal == int.MaxValue ? 0 : maxVal - minVal;
            minVal = prices[i];
            maxVal = int.MinValue;
        }

        previousVal = prices[i];
    }

    return result;
}

Best Solution

Very similar to the previous one, it just add value to the result when current price is bigger than previous value.

public int maxProfit(int[] prices)
{
    int total = 0;
    for (int i = 0; i < prices.Length - 1; i++)
    {
        if (prices[i + 1] > prices[i]) total += prices[i + 1] - prices[i];
    }

    return total;
}