Re-translate the Japanese version (#1871)

* Retranslate Japanese docs with GPT-5.4

* Retranslate Japanese code with GPT-5.4

ja/codes/kotlin/utils/Vertex.kt

@@ -0,0 +1,30 @@
+/**
+ * File: Vertex.kt
+ * Created Time: 2024-01-25
+ * Author: curtishd (1023632660@qq.com)
+ */
+
+package utils
+
+/* 頂点クラス */
+class Vertex(val _val: Int) {
+    companion object {
+        /* 値リスト vals を入力し、頂点リスト vets を返す */
+        fun valsToVets(vals: IntArray): Array<Vertex?> {
+            val vets = arrayOfNulls<Vertex>(vals.size)
+            for (i in vals.indices) {
+                vets[i] = Vertex(vals[i])
+            }
+            return vets
+        }
+
+        /* 頂点リスト vets を入力し、値リスト vals を返す */
+        fun vetsToVals(vets: MutableList<Vertex?>): MutableList<Int> {
+            val vals = mutableListOf<Int>()
+            for (vet in vets) {
+                vals.add(vet!!._val)
+            }
+            return vals
+        }
+    }
+}