test(U4_FRQ.java): test if solution works

src/main/java/Unit4/U4_FRQ.java

@@ -0,0 +1,33 @@
+package Unit4;
+
+public class U4_FRQ {
+    public static void main(String[] args) {
+        longestStreak("CCCCCCAAAAATTT!!!!!!!");
+    }
+
+    public static void longestStreak(String str) {
+
+        int longestStreak = 1;
+        int curStreak = 1;
+        String longestLetter = str.substring(0, 1);
+
+        for (int i = 1; i < str.length(); i++) {
+            String curLetter = str.substring(i, i + 1);
+            String prevLetter = str.substring(i - 1, i);
+
+            if (curLetter.equals(prevLetter)) {
+                curStreak++;
+            } else {
+                curStreak = 1;
+            }
+
+            if (curStreak > longestStreak) {
+                longestStreak = curStreak;
+                longestLetter = prevLetter;
+            }
+
+        }
+
+        System.out.println(longestLetter + " " + longestStreak);
+    }
+}