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

Author: andavid

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

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+/*
+ * @lc app=leetcode id=122 lang=java
+ *
+ * [122] Best Time to Buy and Sell Stock II
+ *
+ * https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/description/
+ *
+ * algorithms
+ * Easy (50.92%)
+ * Total Accepted:    311.1K
+ * Total Submissions: 604.3K
+ * Testcase Example:  '[7,1,5,3,6,4]'
+ *
+ * Say you have an array for which the i^th element is the price of a given
+ * stock on day i.
+ *
+ * Design an algorithm to find the maximum profit. You may complete as many
+ * transactions as you like (i.e., buy one and sell one share of the stock
+ * multiple times).
+ *
+ * Note: You may not engage in multiple transactions at the same time (i.e.,
+ * you must sell the stock before you buy again).
+ *
+ * Example 1:
+ *
+ *
+ * Input: [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.
+ *
+ *
+ * Example 2:
+ *
+ *
+ * Input: [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.
+ * Note that you cannot buy on day 1, buy on day 2 and sell them later, as you
+ * are
+ * engaging multiple transactions at the same time. You must sell before buying
+ * again.
+ *
+ *
+ * Example 3:
+ *
+ *
+ * Input: [7,6,4,3,1]
+ * Output: 0
+ * Explanation: In this case, no transaction is done, i.e. max profit = 0.
+ *
+ */
+class Solution {
+  public int maxProfit(int[] prices) {
+    int profit = 0;
+    int len = prices.length;
+    for (int i = 1; i < len; i++) {
+      if (prices[i] > prices[i-1]) {
+        profit += prices[i] - prices[i-1];
+      }
+    }
+    return profit;
+  }
+}
+