Add solution for ReverseWordsInAStringIII task

Author: andrei-punko

src/main/java/by/andd3dfx/string/ReverseWordsInAStringIII.java

@@ -0,0 +1,27 @@
+package by.andd3dfx.string;
+
+public class ReverseWordsInAStringIII {
+
+    public static String reverseWords(String s) {
+        String[] words = s.split(" ");
+        for (int i = 0; i < words.length; i++) {
+            words[i] = reverse(words[i]);
+        }
+        return String.join(" ", words);
+    }
+
+    private static String reverse(String word) {
+        var chars = word.toCharArray();
+        var n = chars.length;
+        for (int i = 0; i < n / 2; i++) {
+            swap(chars, i, n - 1 - i);
+        }
+        return new String(chars);
+    }
+
+    private static void swap(char[] chars, int i, int j) {
+        var tmp = chars[i];
+        chars[i] = chars[j];
+        chars[j] = tmp;
+    }
+}

src/test/java/by/andd3dfx/string/ReverseWordsInAStringIIITest.java

@@ -0,0 +1,21 @@
+package by.andd3dfx.string;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class ReverseWordsInAStringIIITest {
+
+    @Test
+    public void reverseWords() {
+        assertThat(ReverseWordsInAStringIII.reverseWords("World"))
+            .isEqualTo("dlroW");
+        assertThat(ReverseWordsInAStringIII.reverseWords("a b c"))
+            .isEqualTo("a b c");
+
+        assertThat(ReverseWordsInAStringIII.reverseWords("Let's take LeetCode contest"))
+            .isEqualTo("s'teL ekat edoCteeL tsetnoc");
+        assertThat(ReverseWordsInAStringIII.reverseWords("Mr Ding"))
+            .isEqualTo("rM gniD");
+    }
+}