more arrays

data_structures/arrays/array_leader.py

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+"""
+Given an array arr[] of size n, the task is to find all the Leaders in the array.
+ An element is a Leader if it is greater than all the elements to its right side.
+
+Note: The rightmost element is always a leader. 
+"""
+
+def array_leader(arr):
+    leaders = []
+    for i in range(len(arr)):
+        for j in range(i+1, len(arr)):
+            if arr[i] < arr[j]:
+                break
+        else:
+            leaders.append(arr[i])
+    
+    return " ".join(map(str, leaders))
+
+
+# Test the function with the provided input
+print(array_leader([16, 17, 4, 3, 5, 2]))  # Expected output: 17 5 2

data_structures/arrays/max_product_subarray.py

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+"""
+Given an integer array, the task is to find the maximum product of any subarray. 
+Input: arr[] = {-1, -3, -10, 0, 60}
+Output: 60
+Explanation: The subarray with maximum product is {60}.
+"""
+
+def max_product(arr):
+    result = 0
+
+    for x in range(len(arr)):
+        current_product = 1
+        for y in range(x, len(arr)):
+            current_product *= arr[y]
+            result = max(result, current_product)
+    return result
+
+# Test the function with the provided input
+print(max_product([-1, -3, -10, 0, 60]))  # Expected output: 60

data_structures/arrays/max_subarray.py

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+"""
+Input: arr[] = {2, 3, -8, 7, -1, 2, 3}
+Output: 11
+Explanation: The subarray {7, -1, 2, 3} has the largest sum 11.
+
+Input: arr[] = {-2, -4}
+Output: –2
+Explanation: The subarray {-2} has the largest sum -2.
+
+Input: arr[] = {5, 4, 1, 7, 8}
+Output: 25
+Explanation: The subarray {5, 4, 1, 7, 8} has the largest sum 25.
+"""
+
+def max_subarray(arr):
+    result = arr[0]
+
+    for x in range(len(arr)):
+        current_sum = 0
+        for y in range(x, len(arr)):
+            current_sum += arr[y]
+            result = max(result, current_sum)
+    return result
+
+# Test the function with the provided inputs
+print(max_subarray([2, 3, -8, 7, -1, 2, 3]))  # Expected output: 11
+print(max_subarray([-2, -4]))  # Expected output: -2
+print(max_subarray([5, 4, 1, 7, 8]))  # Expected output: 25

data_structures/arrays/missing_number.py

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+'''
+Given an array arr[] of size n-1 with integers in the range of [1, n], the task is to find the missing number from the first N integers.
+
+Note: There are no duplicates in the list.
+
+Input: arr[] = {1, 2, 4, 6, 3, 7, 8} , n = 8
+Output: 5
+Explanation: Here the size of the array is 8, so the range will be [1, 8]. The missing number between 1 to 8 is 5
+
+Input: arr[] = {1, 2, 3, 5}, n = 5
+Output: 4
+Explanation: Here the size of the array is 4, so the range will be [1, 5]. The missing number between 1 to 5 is 4
+'''
+
+def find_missing_number(arr, n):
+    hash = [0] * (n+1)
+
+    for num in arr:
+        hash[num] += 1
+    for i in range(1, (n+1)):
+        if hash[i] == 0:
+            return i
+    return -1
+
+print(find_missing_number([1,2,3,4,6,7,8], 8))

data_structures/arrays/rotate_elements.py

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+"""
+Given an Array of size N and a value K, 
+around which we need to right rotate the array. 
+How do you quickly print the right rotated array?
+
+Input: Array[] = {1, 3, 5, 7, 9}, K = 2.
+Output: 7 9 1 3 5
+Explanation:
+After 1st rotation – {9, 1, 3, 5, 7}After 2nd rotation – {7, 9, 1, 3, 5}
+"""
+
+def right_rotate(arr, k):
+    n = len(arr)
+    k = k % n
+    arr = arr[n-k:] + arr[:n-k]
+    return arr
+
+# Test the function with the provided input
+print(right_rotate([1, 3, 5, 7, 9], 2))  # Expected output: [7, 9, 1, 3, 5]