DEV: Implementing Alternative String Arrange (#6551)

src/main/java/com/thealgorithms/strings/AlternativeStringArrange.java

@@ -0,0 +1,48 @@
+package com.thealgorithms.strings;
+
+/**
+ * This class provides a method to arrange two strings by alternating their characters.
+ * If one string is longer, the remaining characters of the longer string are appended at the end.
+ * <p>
+ * Example:
+ * Input: "abc", "12345"
+ * Output: "a1b2c345"
+ * <p>
+ * Input: "abcd", "12"
+ * Output: "a1b2cd"
+ *
+ * @author Milad Sadeghi
+ */
+public final class AlternativeStringArrange {
+
+    // Private constructor to prevent instantiation
+    private AlternativeStringArrange() {
+    }
+
+    /**
+     * Arranges two strings by alternating their characters.
+     *
+     * @param firstString  the first input string
+     * @param secondString the second input string
+     * @return a new string with characters from both strings arranged alternately
+     */
+    public static String arrange(String firstString, String secondString) {
+        StringBuilder result = new StringBuilder();
+        int length1 = firstString.length();
+        int length2 = secondString.length();
+        int minLength = Math.min(length1, length2);
+
+        for (int i = 0; i < minLength; i++) {
+            result.append(firstString.charAt(i));
+            result.append(secondString.charAt(i));
+        }
+
+        if (length1 > length2) {
+            result.append(firstString.substring(minLength));
+        } else if (length2 > length1) {
+            result.append(secondString.substring(minLength));
+        }
+
+        return result.toString();
+    }
+}