deepcodingios
diff --git a/‎src/Hashing/FirstRepeatingElement.java‎
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Lines changed: 0 additions & 39 deletions
diff --git a/‎src/Hashing/HashMapProblems.java‎
Lines changed: 121 additions & 0 deletions b/‎src/Hashing/HashMapProblems.java‎
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+package Hashing;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+public class HashMapProblems {
+    public static void main(String[] args) {
+
+        ArrayList<Integer> list = new ArrayList<>();
+        list.add(10);
+        list.add(5);
+        list.add(3);
+        list.add(4);
+        list.add(3);
+        list.add(5);
+        list.add(6);
+
+        int answer = findFirstRepeatingElement(list);
+        int array [] = {2, 7, 11, 15};
+        int array2 [] = {2, 2, 11, 15, 3,4,5};
+        int target = 9;
+        int [] result = twoSum(array,target);
+        System.out.println("Array with Indices is " + result[0] + result[1]);
+        System.out.println("Repeating Element is " + answer);
+
+        commonElements(array,array2);
+
+    }
+
+    static ArrayList<Integer> commonElements(int[] A, int[] B) {
+
+        ArrayList<Integer> commonElements = new ArrayList<Integer>;
+
+        HashMap<Integer,Integer> hashMap_1 = new HashMap<>();
+
+        for (int i = 0; i < A.length; i++){
+            if (hashMap_1.containsKey(A[i])){
+                int value = hashMap_1.get(A[i]);
+                hashMap_1.put(A[i],value++);
+            }else {
+                hashMap_1.put(A[i], 1);
+            }
+        }
+
+        HashMap<Integer,Integer> hashMap_2 = new HashMap<>();
+
+        for (int i = 0; i < B.length; i++){
+            if (hashMap_2.containsKey(B[i])){
+                int value = hashMap_2.get(B[i]);
+                hashMap_2.replace(B[i],value+1);
+            }else {
+                hashMap_2.put(B[i], 1);
+            }
+        }
+
+        for (int i = 0; i < A.length; i++){
+
+            if (hashMap_2.containsKey(A[0])){
+                boolean test = false;
+                for (int element : A) {
+                    if (element == A[0]) {
+                        test = true;
+                        break;
+                    }
+                }
+                if (!test){
+
+                }
+            }
+
+        }
+
+
+        System.out.println(hashMap_1);
+        System.out.println(hashMap_2);
+
+        return commonElements;
+    }
+
+    static int[] twoSum( int[] A, int B) {
+
+        int[] indicesArray = new int[2];
+
+        int start = 0; int end = A.length -1;
+
+        while (start < end){
+
+            if(A[start]+A[end] == B){
+                indicesArray[0] = start;
+                indicesArray[1] = end;
+
+                return indicesArray;
+            }
+
+            if (A[start]+A[end] > B){
+                end--;
+            }else {
+                start++;
+            }
+        }
+
+        return indicesArray;
+    }
+
+    static int findFirstRepeatingElement(ArrayList<Integer> arrayList){
+
+        int repeatingElement = -1;
+
+        HashMap<Integer, Integer> map = new HashMap<>();
+
+        for (int i = arrayList.size()-1; i > 0; i--) {
+
+            if (map.containsKey(arrayList.get(i))) {
+                repeatingElement = arrayList.get(i);
+            }else {
+                map.put(arrayList.get(i),1);
+            }
+        }
+        return repeatingElement;
+    }
+}