add some array playing

arrays_and_strings/array-check-if-exist.py

@@ -0,0 +1,27 @@
+"""
+Given an array arr of integers, check if there exist two indices i and j such that :
+
+i != j
+0 <= i, j < arr.length
+arr[i] == 2 * arr[j]
+"""
+
+
+def check_if_exist(arr: list[int]) -> bool:
+        
+        aux_dict = {}
+        
+        for i, num in enumerate(arr):
+            aux_dict[2*num] = i
+        
+        for j, num in enumerate(arr):
+            if num in aux_dict.keys() and j != aux_dict[num]:
+                return (j, aux_dict[num])
+                
+        
+        return False
+
+if __name__ == "__main__":
+
+    arr = [-2, 0, 10, -19, 4, 6, -8]
+    print(check_if_exist(arr))