[0213] 2193번 - 이친수

src/Problem2193.java

@@ -0,0 +1,36 @@
+import java.io.IOException;
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+
+public class Problem2193 {
+    public static void main(String[] args) throws IOException{
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        int n = Integer.parseInt(br.readLine());
+
+        Long before1 = 1L;
+        Long before2 = 1L;
+
+        if (n == 1 || n == 2) {
+            bw.write("1");
+            bw.flush();
+            bw.close();
+            return;
+        }
+
+        for(int i = 3; i <= n ; i++) {
+            Long temp = before2;
+            before2 = before1;
+            before1 = temp + before2;
+        }
+
+        bw.write(String.valueOf(before1));
+        bw.flush();
+        bw.close();
+
+
+    }
+}