Added file 1290.cpp

Author: Kavisha20340

leetcode/cpp/linkedlist/1290.cpp

@@ -0,0 +1,28 @@
+/**
+ * Definition for singly-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:
+    int getDecimalValue(ListNode* head) {
+    	int answer = 0;
+    	vector<int> v;
+    	while(head){
+    		v.push_back(head->val);
+    		head = head->next;
+    	}
+    	reverse(v.begin(),v.end());
+    	for (int i = 0; i < v.size(); i++)
+    		if(v.at(i))
+    			answer += pow(2,i);
+        return answer;
+    }
+};
+
+