edit 121

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_121.java

@@ -14,41 +14,31 @@ If you were only permitted to complete at most one transaction (ie, buy one and
 max. difference = 6-1 = 5 (not 7-1 = 6, as selling price needs to be larger than buying price)
 
 
- Example 2:
+Example 2:
 Input: [7, 6, 4, 3, 1]
 Output: 0
 
 In this case, no transaction is done, i.e. max profit = 0.*/
 
 public class _121 {
+
     /**Pretty straightforward, sell before you buy, keep a global maxProfit variable, update it along the way if necessary.*/
-    public int maxProfit_20160924(int[] prices) {
-        if(prices == null || prices.length < 2) return 0;
+
+    /**The key here is that you'll have to buy first, before you can sell.
+     * That means, if the lower price comes after a higher price, their combination won't work! Since you cannot sell first
+     * before you buy it.*/
+    public int maxProfit(int[] prices) {
+        if (prices == null || prices.length < 2) return 0;
         int minBuy = prices[0];
         int maxSell = prices[1];
         int maxProfit = (maxSell - minBuy) > 0 ? (maxSell - minBuy) : 0;
-        for(int i = 1; i < prices.length; i++){
+        for (int i = 1; i < prices.length; i++) {
             minBuy = Math.min(minBuy, prices[i]);
             maxProfit = Math.max(maxProfit, prices[i] - minBuy);
         }
         return maxProfit;
     }
 
-/**The key here is that you'll have to buy first, before you can sell.
- * That means, if the lower price comes after a higher price, their combination won't work! Since you cannot sell first
- * before you buy it.*/
-    public int maxProfit(int[] prices) {
-        //use current price to deduct the previous min to get current profit, and then take the max from previousMax and this newly calculated max
-        if(prices == null || prices.length < 2) return 0;
-        int min = prices[0], prevProf = 0, currPro = 0;
-        for(int i = 1; i < prices.length; i++){
-            currPro = Math.max(prices[i] - min, prevProf);
-            min = Math.min(min, prices[i]);
-            prevProf = currPro;
-        }
-        return currPro;
-    }
-    
     public static void main(String...strings){
 //        int[] prices = new int[]{7,1,5,3,6,4};
 //        int[] prices = new int[]{7,6,4,3,1};