review 3

Author: rchen102

Java/leetcode 1.java

@@ -5,12 +5,15 @@ public int[] twoSum(int[] nums, int target) {
         if (nums == null || nums.length == 0) return res;
         Map<Integer, Integer> map = new HashMap<>();
         for (int i = 0; i < nums.length; i++) {
-            if (map.containsKey(target-nums[i])) {
-                res[0] = i;
-                res[1] = map.get(target-nums[i]);
+            int wanted = target - nums[i];
+            if (map.containsKey(wanted)) {
+                res[0] = map.get(wanted);
+                res[1] = i;
                 return res;
             }
-            map.put(nums[i], i);
+            else {
+                map.put(nums[i], i);
+            }
         }
         return res;
     }

Java/leetcode 11.java

@@ -5,11 +5,11 @@
 class Solution {
     public int maxArea(int[] height) {
         int res = 0;
-        if (height == null || height.length == 0) return res;
         int left = 0, right = height.length - 1;
         while (left < right) {
-            int area = Math.min(height[left], height[right]) * (right - left);
-            res = Math.max(res, area);
+            int row = right - left;
+            int tall = Math.min(height[left], height[right]);
+            res = Math.max(res, row * tall);
             if (height[left] < height[right]) left++;
             else if (height[left] > height[right]) right--;
             else {