Merge pull request #974 from ayush91985/main

added linkde list program

Author: Sirajmolla

C++/Detect loop in linked list_ayush91985.cpp

@@ -0,0 +1,70 @@
+// C++ program to detect loop in a linked list
+#include <bits/stdc++.h>
+using namespace std;
+
+/* Link list node */
+struct Node {
+	int data;
+	struct Node* next;
+};
+
+void push(struct Node** head_ref, int new_data)
+{
+	/* allocate node */
+	struct Node* new_node = new Node;
+
+	/* put in the data */
+	new_node->data = new_data;
+
+	/* link the old list off the new node */
+	new_node->next = (*head_ref);
+
+	/* move the head to point to the new node */
+	(*head_ref) = new_node;
+}
+
+// Returns true if there is a loop in linked list
+// else returns false.
+bool detectLoop(struct Node* h)
+{
+	unordered_set<Node*> s;
+	while (h != NULL) {
+		// If this node is already present
+		// in hashmap it means there is a cycle
+		// (Because you will be encountering the
+		// node for the second time).
+		if (s.find(h) != s.end())
+			return true;
+
+		// If we are seeing the node for
+		// the first time, insert it in hash
+		s.insert(h);
+
+		h = h->next;
+	}
+
+	return false;
+}
+
+/* Driver program to test above function*/
+int main()
+{
+	/* Start with the empty list */
+	struct Node* head = NULL;
+
+	push(&head, 20);
+	push(&head, 4);
+	push(&head, 15);
+	push(&head, 10);
+
+	/* Create a loop for testing */
+	head->next->next->next->next = head;
+
+	if (detectLoop(head))
+		cout << "Loop found";
+	else
+		cout << "No Loop";
+
+	return 0;
+}
+// This code is contributed by Geetanjali

LeetCode/Largest subarray with 0 sum/Largest subarray 0 sum.cpp

@@ -0,0 +1,86 @@
+
+//SOLUTION
+  class Solution
+{
+
+ 
+public:
+ 
+int maxLen (vector < int >&A, int n) 
+ 
+  {
+    
+ 
+int maxi = 0;
+    
+ 
+int sum = 0;
+    
+ 
+unordered_map < int, int >m;
+    
+ 
+for (int i = 0; i < n; i++)
+      
+ 
+      {
+	
+ 
+sum += A[i];
+	
+ 
+if (sum == 0)
+	  
+ 
+	  {
+	    
+ 
+maxi = i + 1;
+	  
+ 
+}
+	
+ 
+	else
+	  
+ 
+	  {
+	    
+ 
+if (m.find (sum) != m.end ())
+	      
+ 
+	      {
+		
+ 
+maxi = max (maxi, i - m[sum]);
+	      
+ 
+}
+	    
+ 
+	    else
+	      
+ 
+	      {
+		
+ 
+m[sum] = i;
+	      
+ 
+}
+	  
+ 
+}
+      
+ 
+}
+    
+ 
+return maxi;
+  
+ 
+}
+
+ 
+};

LeetCode/Largest subarray with 0 sum/Readme.md

@@ -0,0 +1,19 @@
+Given an array having both positive and negative integers. The task is to compute the length of the largest subarray with sum 0.
+
+Example 1:
+
+Input:
+N = 8
+A[] = {15,-2,2,-8,1,7,10,23}
+Output: 5
+Explanation: The largest subarray with
+sum 0 will be -2 2 -8 1 7.
+Your Task:
+You just have to complete the function maxLen() which takes two arguments an array A and n, where n is the size of the array A and returns the length of the largest subarray with 0 sum.
+
+Expected Time Complexity: O(N).
+Expected Auxiliary Space: O(N).
+
+Constraints:
+1 <= N <= 105
+-1000 <= A[i] <= 1000, for each valid i