Partition List

Linked List/C++/10_Partition List.cpp

@@ -0,0 +1,61 @@
+
+#include <iostream>
+#include <vector>
+#include <climits>
+using namespace std;
+//definition of a single linked list
+  struct ListNode {
+      int val;
+      ListNode *next;
+    ListNode() : val(0), next(nullptr) {}
+    ListNode(int x) : val(x), next(nullptr) {}
+     ListNode(int x, ListNode *next) : val(x), next(next) {}
+ };
+
+
+
+
+class Solution {
+public:
+    ListNode* partition(ListNode* head, int x) {
+        ListNode *n = new ListNode();//input 
+        ListNode *tail = n;//dummy
+        ListNode *q = new ListNode();
+        ListNode *t = q;//dummy variable
+        while(head!=NULL){//for iteraing
+            if(head->val>=x){
+                t->next=head;
+                t=t->next;//the t dummy or storing the nodes which has values greater than or equal to given value
+            }
+            else if(head->val<x){//for storing the nodes which has value less than the given and,
+                tail->next=head;
+                tail=tail->next;
+            }
+            head=head->next;
+        }
+        tail->next=q->next;
+        t->next=NULL;
+        return n->next;//printing the final one
+    }
+};
+int main()
+{
+
+    int x,n;//the 
+    cin>>x;
+    cin>>n;
+    int head[n];
+    for(int i=0;i<n;i++)
+    {
+        cin>>head[i];
+    }
+     partition(head, x);//calling the func
+     return 0; 
+
+}
+/*Input: head = [1,4,3,2,5,2], x = 3
+Output: [1,2,2,4,3,5]
+Example 2:
+
+Input: head = [2,1], x = 2
+Output: [1,2]