백준/단계별: 15439 베라의 패션 (#23)

src/baekjoon/step/combinatoric/PROB15439.java

@@ -0,0 +1,24 @@
+package baekjoon.step.combinatoric;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class PROB15439 {
+
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static int N;
+    static int cnt;
+
+    public static void main(String[] args) throws IOException {
+        N = Integer.parseInt(br.readLine());
+
+        for (int i = 0; i < N; i ++) {
+            for (int j = i + 1; j < N; j ++) {
+                cnt ++;
+            }
+        }
+
+        System.out.println(cnt * 2);
+    }
+}