rubythonode
diff --git a/Collapse file
‎src/test/java/exercise/CalenderExample.java‎
Copy file name to clipboard
+97Lines changed: 97 additions & 0 deletions b/Collapse file
‎src/test/java/exercise/CalenderExample.java‎
Copy file name to clipboard
+97Lines changed: 97 additions & 0 deletions
diff --git a/Collapse file
‎src/test/java/exercise/FactorialZeroCount.java‎
Copy file name to clipboard
+54Lines changed: 54 additions & 0 deletions b/Collapse file
‎src/test/java/exercise/FactorialZeroCount.java‎
Copy file name to clipboard
+54Lines changed: 54 additions & 0 deletions
diff --git a/Collapse file
‎src/test/java/exercise/NoTempSwapTest.java‎
Copy file name to clipboard
+28Lines changed: 28 additions & 0 deletions b/Collapse file
‎src/test/java/exercise/NoTempSwapTest.java‎
Copy file name to clipboard
+28Lines changed: 28 additions & 0 deletions
@@ -0,0 +1,97 @@
+package exercise;
+
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+public class CalenderExample {
+
+    /*
+        TASK
+        2017년 1월 1일은 일요일이다.
+        2017년 어느날의 월, 일을 입력받아 요일을 반환하는 함수를 구현한다.
+
+        2017년 2월은 28일까지 있다.
+        요일은 월~일을 0~6으로 표현한다.
+        예를 들어 월요일이면 0을 반환하고, 토요일은 5, 일요일은 6을 반환한다.
+     */
+
+    @Test
+    public void test() {
+        Calendar c = new Calendar();
+        assertThat(c.getDay(3, 20), is("금요일"));
+    }
+
+    public int getDayOfWeek(int month, int day) {
+        int[] daysInMonth = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+        int count = 0;
+
+        for (int i = 1; i < month; i++) {
+            count += daysInMonth[i];
+        }
+        count += day;
+        count += 5;
+        return count % 7;
+    }
+
+    public class Calendar {
+        private Map<Integer, Integer> calender;
+
+        public Calendar() {
+            this.calender = buildCalender();
+        }
+
+        public String getDay(int month, int day) {
+            switch (getDayIntFormat(month, day)) {
+                case 0:
+                    return "월요일";
+                case 1:
+                    return "화요일";
+                case 2:
+                    return "수요일";
+                case 3:
+                    return "목요일";
+                case 4:
+                    return "금요일";
+                case 5:
+                    return "토요일";
+                case 6:
+                    return "일요일";
+                default:
+                    return null;
+            }
+        }
+
+        private int getDayIntFormat(int month, int day) {
+            for (Map.Entry<Integer, Integer> entry : calender.entrySet()) {
+                int sum = 0;
+                if (entry.getKey() == month) {
+                    return (sum + day + 5) % 7;
+                }
+                sum += entry.getValue();
+            }
+            return -1;
+        }
+
+        private Map<Integer, Integer> buildCalender() {
+            Map<Integer, Integer> calender = new HashMap<>();
+            calender.put(1, 31);
+            calender.put(2, 28);
+            calender.put(3, 31);
+            calender.put(4, 30);
+            calender.put(5, 31);
+            calender.put(6, 30);
+            calender.put(7, 31);
+            calender.put(8, 31);
+            calender.put(9, 30);
+            calender.put(10, 31);
+            calender.put(11, 30);
+            calender.put(12, 31);
+            return calender;
+        }
+    }
+}
@@ -0,0 +1,54 @@
+package exercise;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+public class FactorialZeroCount {
+
+    /*
+        TASK
+        n!의 결과값에서 0의 개수를 구한다.
+     */
+
+    @Test
+    public void test() {
+
+        assertThat(countZero1(getFactorial(5)), is(1));
+        assertThat(countZero1(getFactorial(12)), is(2));
+        assertThat(countZero2(5), is(1));
+        assertThat(countZero2(12), is(2));
+    }
+
+    public int getFactorial(int num) {
+        int result = 1;
+        for (int i = 1; i <= num; i++) {
+            result *= i;
+        }
+        return result;
+    }
+
+    public int countZero1(int num) {
+        int count = 0;
+        while (num % 10 == 0) {
+            num /= 10;
+            count++;
+        }
+        return count;
+    }
+
+
+    // 5가 얼마나 곱해졌는지가 중요하다.
+    public int countZero2(int num) {
+        int count = 0;
+        for (int i = 5; i <= num; i += 5) {
+            int base = i;
+            while (base % 5 == 0) {
+                base /= 5;
+                count++;
+            }
+        }
+        return count;
+    }
+}
@@ -0,0 +1,28 @@
+package exercise;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+public class NoTempSwapTest {
+    @Test
+    public void test() {
+        int a = 4;
+        int b = 3;
+
+        int[] result = swap(a, b);
+        assertThat(result[0] == 3, is(true));
+        assertThat(result[1] == 4, is(true));
+    }
+
+    public int[] swap(int a, int b) {
+        int[] result = new int[2];
+        a = a + b;
+        b = a - b;
+        a = a - b;
+        result[0] = a;
+        result[1] = b;
+        return result;
+    }
+}