BOJ_1244 : 스위치 켜고 끄기

Author: spring0913

week2/BOJ_1244(스위치 켜고 끄기).java

@@ -0,0 +1,52 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    public static int N;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        N = Integer.parseInt(br.readLine());
+        boolean[] arr = new boolean[N+1];
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        for(int i=1; i<=N; i++) {
+            arr[i] = (Integer.parseInt(st.nextToken()) == 1);
+        }
+        int m = Integer.parseInt(br.readLine());
+        for(int i=0; i<m; i++) {
+            st = new StringTokenizer(br.readLine());
+            int student = Integer.parseInt(st.nextToken());
+            int num = Integer.parseInt(st.nextToken());
+            updateSwitch(arr, student, num);
+        }
+        StringBuffer sb = new StringBuffer();
+        for(int i=1; i<=N; i++) {
+            sb.append(arr[i] ? '1' : '0');
+            if(i % 20 == 0) {
+                sb.append('\n');
+            }else {
+                sb.append(' ');
+            }
+        }
+        System.out.println(sb);
+    }
+
+    public static void updateSwitch(boolean[] arr, int student, int num) {
+        if(student == 1) {
+            for(int i=1; i<=N; i++) {
+                if(i % num == 0) {
+                    arr[i] = !arr[i];
+                }
+            }
+        }else {
+            for(int i=0; (num-i>=1) && (num+i <= N); i++) {
+                if(arr[num-i] == arr[num+i]) {
+                    arr[num-i] = arr[num+i] = !arr[num+i];
+                }else {
+                    return;
+                }
+            }
+        }
+    }
+}