addUptoTarget

addUptoTarget

@@ -0,0 +1,69 @@
+1)Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
+
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+
+You can return the answer in any order.
+
+Example 1:
+
+Input: nums = [2,7,11,15], target = 9
+Output: [0,1]
+Output: Because nums[0] + nums[1] == 9, we return [0, 1].
+
+Sol)
+
+Time Complexity - O(n2)
+
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+
+
+        int[] arr = new int[2];
+        int n = nums.length ;
+
+        for( int i = 0 ; i < n ; i++)
+        {
+            for( int j =i+1 ; j < n ; j++)
+            {
+               if( nums[i] + nums[j] == target)
+               {
+                   arr[0] = i;
+                   arr[1] = j;
+               } 
+            }  
+        }
+
+       return arr; 
+    }
+}
+
+
+Time complexity = O(n)
+Space Complexity = O(n)
+
+
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+
+        int arr[] = new int[2];
+
+        HashMap<Integer,Integer> map = new HashMap();
+
+
+        for( int i = 0 ;i< nums.length ; i++)
+            map.put(nums[i],i);
+
+        for(int i = 0 ; i< nums.length ; i++)
+        {
+            if(map.containsKey(target - nums[i]) && i != map.get(target - nums[i]))
+            {
+               arr[0] = i ;
+               arr[1] = map.get(target - nums[i]);
+            }
+        }
+
+
+       return arr; 
+
+    }
+}