1544. Make The String Great

algorithms-and-data-structures/src/main/java/com/xtenzq/leetcode/MakeGood.java

@@ -0,0 +1,28 @@
+package com.xtenzq.leetcode;
+
+import java.util.Stack;
+
+public class MakeGood {
+
+    public static String makeGood(String s) {
+        if (s.length() == 1) {
+            return s;
+        }
+        Stack<Character> chars = new Stack<>();
+        chars.push(s.charAt(0));
+        for (int i = 1; i < s.length(); i++) {
+            if (!chars.empty() && Math.abs((int)s.charAt(i) - (int)chars.peek()) == 32) {
+                chars.pop();
+            } else {
+                chars.push(s.charAt(i));
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (char c : chars) {
+            sb.append(c);
+        }
+        return sb.toString();
+    }
+
+}

algorithms-and-data-structures/src/test/java/com/xtenzq/leetcode/MakeGoodTest.java

@@ -0,0 +1,24 @@
+package com.xtenzq.leetcode;
+
+import org.junit.jupiter.api.Test;
+
+import static com.xtenzq.leetcode.MakeGood.makeGood;
+import static org.junit.jupiter.api.Assertions.*;
+
+class MakeGoodTest {
+
+    @Test
+    void makeGood_case1() {
+        assertEquals("leetcode", makeGood("leEeetcode"));
+    }
+
+    @Test
+    void makeGood_case2() {
+        assertEquals("", makeGood("abBAcC"));
+    }
+
+    @Test
+    void makeGood_case3() {
+        assertEquals("s", makeGood("s"));
+    }
+}