122.best-time-to-buy-and-sell-stock-ii.java

/*
 * @lc app=leetcode id=122 lang=java
 *
 * [122] Best Time to Buy and Sell Stock II
 */

// @lc code=start
class Solution {
    public int maxProfit2(int[] prices) {
        int valley = prices[0];
        int peak = prices[0];
        int maxProfit = 0;

        for (int i = 0; i < prices.length - 1; i++) {
            while (i < prices.length - 1 && prices[i] >= prices[i + 1]) i++;
            valley = prices[i];

            while (i < prices.length - 1 && prices[i] <= prices[i + 1]) i++;
            peak = prices[i];

            maxProfit += peak - valley;
        }
        return maxProfit;
    }

    public int maxProfit(int[] prices) {
        int maxProfit = 0;

        for (int i = 1; i < prices.length; i++) {
            if (prices[i] > prices[i - 1]) {
                maxProfit += prices[i] - prices[i - 1];
            }
        }
        return maxProfit;
    }
}
// @lc code=end