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LeetCode #2 Two Sum
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| class Solution { | |
| public int[] twoSum(int[] nums, int target) { | |
| // 1. initialize HashMap for {Number -> Index} | |
| Map<Integer, Integer> map = new HashMap<>(); | |
| // 2. iterate the array | |
| for (int i = 0; i < nums.length; i ++) { | |
| // 3. check if such 'num2' exists in the hashmap | |
| int num2 = target - nums[i]; | |
| if (map.containsKey(num2)) { | |
| return new int[]{i, map.get(num2)}; | |
| } | |
| // 4. if not exist, add new pair | |
| map.put(nums2, i); | |
| } | |
| return null; | |
| } | |
| } |
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