leetcode-2021.3.27 (examplehub#88)

realDuYuanChao · github-actions · web-flow · commit 325a0e382092 · 2021-03-27T21:08:01.000+08:00
* convert-binary-number-in-a-linked-list-to-integer

* Formatted with Google Java Formatter

Co-authored-by: github-actions &lt;${GITHUB_ACTOR}@users.noreply.github.com&gt;
diff --git a/src/main/java/com/examplehub/leetcode/easy/ConvertBinaryNumberInALinkedListToInteger.java b/src/main/java/com/examplehub/leetcode/easy/ConvertBinaryNumberInALinkedListToInteger.java
@@ -0,0 +1,18 @@
+package com.examplehub.leetcode.easy;
+
+import com.examplehub.leetcode.ListNode;
+
+/*
+ * https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer/
+ */
+public class ConvertBinaryNumberInALinkedListToInteger {
+
+  public static int solution1(ListNode head) {
+    StringBuilder builder = new StringBuilder();
+    while (head != null) {
+      builder.append(head.val);
+      head = head.next;
+    }
+    return Integer.parseInt(builder.toString(), 2);
+  }
+}
diff --git a/src/test/java/com/examplehub/leetcode/easy/ConvertBinaryNumberInALinkedListToIntegerTest.java b/src/test/java/com/examplehub/leetcode/easy/ConvertBinaryNumberInALinkedListToIntegerTest.java
@@ -0,0 +1,25 @@
+package com.examplehub.leetcode.easy;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import com.examplehub.leetcode.ListNode;
+import org.junit.jupiter.api.Test;
+
+class ConvertBinaryNumberInALinkedListToIntegerTest {
+  @Test
+  void testSolution1() {
+    ListNode head = new ListNode(1);
+    ListNode node2 = new ListNode(0);
+    ListNode node3 = new ListNode(1);
+    head.next = node2;
+    node2.next = node3;
+
+    assertEquals(ConvertBinaryNumberInALinkedListToInteger.solution1(head), 5);
+
+    head = new ListNode(1);
+    assertEquals(ConvertBinaryNumberInALinkedListToInteger.solution1(head), 1);
+
+    head = new ListNode(0);
+    assertEquals(ConvertBinaryNumberInALinkedListToInteger.solution1(head), 0);
+  }
+}
