Created intersection-of-two-linked-lists.cpp

160-intersection-of-two-linked-lists.cpp

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+// Given the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. 
+// If the two linked lists have no intersection at all, return null.
+
+// Time:  O(m + n)
+// Space: O(1)
+
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode(int x) : val(x), next(NULL) {}
+ * };
+ */
+
+class Solution {
+public:
+    ListNode *getIntersectionNode(ListNode *headA, ListNode *headB) {
+        ListNode *curA = headA, *curB = headB;
+        while (curA != curB) {
+            curA = curA ? curA->next : headB;
+            curB = curB ? curB->next : headA;
+        }
+        return curA;
+    }
+};