update

1 files changed, 57 insertions, 0 deletions

diff --git a/1721/main.cpp b/1721/main.cpp
new file mode 100644
index 0000000..e707f35
--- /dev/null
+++ b/1721/main.cpp
@@ -0,0 +1,57 @@
+#include "header.hpp"
+
+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:
+  static ListNode *swapNodes(ListNode *head, int k) {
+    auto iter = head;
+    int counter = 1;
+    std::vector<ListNode *> dummy;
+    while (iter->next != nullptr) {
+      dummy.push_back(iter);
+      iter = iter->next;
+      counter++;
+    }
+    dummy.push_back(iter);
+
+    std::cout << "counter: " << counter << "\n";
+
+    std::swap(static_cast<ListNode *>(dummy[k - 1])->val,
+              static_cast<ListNode *>(dummy[counter - k])->val);
+
+    return head;
+  }
+};
+
+int main(int argc, char **argv) {
+  ListNode *l1 = new ListNode;
+  ListNode *l2 = new ListNode;
+  ListNode *l3 = new ListNode;
+  ListNode *l4 = new ListNode;
+  ListNode *l5 = new ListNode;
+  l1->val = 1;
+  l2->val = 2;
+  l3->val = 3;
+  l4->val = 4;
+  l5->val = 5;
+  l1->next = l2;
+  l2->next = l3;
+  l3->next = l4;
+  l4->next = l5;
+  l5->next = nullptr;
+
+  auto head = Solution::swapNodes(l1, 2);
+
+  while (head->next != nullptr) {
+    std::cout << head->val << ",";
+    head = head->next;
+  }
+  std::cout << "\n";
+}