Add basic Algorithm

Author: jbee37142

…gorithm/CharacterCompressWithLength.java …m/basic/CharacterCompressWithLength.javasrc/test/java/algorithm/CharacterCompressWithLength.java renamed to src/test/java/algorithm/basic/CharacterCompressWithLength.java src/test/java/algorithm/CharacterCompressWithLength.java renamed to src/test/java/algorithm/basic/CharacterCompressWithLength.java

@@ -1,4 +1,4 @@
-package algorithm;
+package algorithm.basic;
 
 import org.junit.Test;
 
@@ -30,11 +30,10 @@ private String RunLengthCompress_USE_HASHMAP(String str) {
         Map<Character, Integer> charCounter = new HashMap<>(str.length());
 
         for (char c : str.toCharArray()) {
-            if (charCounter.containsKey(c)) {
-                charCounter.put(c, charCounter.get(c) + 1);
-            } else {
-                charCounter.put(c, 1);
+            if (!charCounter.containsKey(c)) {
+                charCounter.put(c, 0);
             }
+            charCounter.put(c, charCounter.get(c) + 1);
         }
         StringBuilder sb = new StringBuilder();
         charCounter.forEach((chr, count) -> sb.append(chr + count.toString()));

src/test/java/algorithm/basic/FrequencyStringInDocument.java

@@ -0,0 +1,49 @@
+package algorithm.basic;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+
+public class FrequencyStringInDocument {
+
+    /*
+        TASK
+        주어진 문서(단어별로 나뉘어진 배열)에서 특정 단어의 빈도를 구한다.
+     */
+
+    @Test
+    public void test() {
+        String[] strArr = new String[100];
+        assertThat(0, is(countStringInDocs(strArr, null)));
+        strArr[0] = "jbee";
+        assertThat(1, is(countStringInDocs(strArr, "jbee")));
+        strArr[1] = "jbee";
+        assertThat(2, is(countStringInDocs(strArr, "jbee")));
+        strArr[2] = "jbee";
+        assertThat(3, is(countStringInDocs(strArr, "jbee")));
+    }
+
+    private int countStringInDocs(String[] strArr, String target) {
+        if (strArr == null || target == null) return 0;
+
+        Map<String, Integer> countString = new HashMap<>();
+        Arrays.stream(strArr).forEach(str -> {
+            if (!countString.containsKey(str)) {
+                countString.put(str, 0);
+            }
+            countString.put(str, countString.get(str) + 1);
+        });
+
+        if (countString.get(target) == null) {
+            return 0;
+        }
+
+        return countString.get(target);
+    }
+}

src/test/java/algorithm/IsAnagram.java …test/java/algorithm/basic/IsAnagram.javasrc/test/java/algorithm/IsAnagram.java renamed to src/test/java/algorithm/basic/IsAnagram.java src/test/java/algorithm/IsAnagram.java renamed to src/test/java/algorithm/basic/IsAnagram.java

@@ -1,4 +1,4 @@
-package algorithm;
+package algorithm.basic;
 
 import org.junit.Test;
 

…est/java/algorithm/StringParseToInt.java …va/algorithm/basic/StringParseToInt.javasrc/test/java/algorithm/StringParseToInt.java renamed to src/test/java/algorithm/basic/StringParseToInt.java src/test/java/algorithm/StringParseToInt.java renamed to src/test/java/algorithm/basic/StringParseToInt.java

@@ -1,4 +1,4 @@
-package algorithm;
+package algorithm.basic;
 
 import org.junit.Test;
 

…a/algorithm/UniqueCharacterInString.java …rithm/basic/UniqueCharacterInString.javasrc/test/java/algorithm/UniqueCharacterInString.java renamed to src/test/java/algorithm/basic/UniqueCharacterInString.java src/test/java/algorithm/UniqueCharacterInString.java renamed to src/test/java/algorithm/basic/UniqueCharacterInString.java

@@ -1,4 +1,4 @@
-package algorithm;
+package algorithm.basic;
 
 import org.junit.Test;