上传文件至 ''

A_IPChecker.java

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+package aoj.contest1399;
+
+import java.util.Scanner;
+
+public class A_IPChecker {
+    public static void main(String[] args) {
+        for (Scanner cin = new Scanner(System.in);
+             cin.hasNext();
+             System.out.println(check(cin.nextLine().split("\\."))?"Y":"N"));
+
+    }
+    private static boolean check(String[] ss) {
+        if (ss.length != 4)
+            return false;
+        for (String s : ss)
+            if (!check(s))
+                return false;
+        return true;
+    }
+    private static boolean check(String s) {
+        int ip = 0;
+        try {
+            ip = Integer.parseInt(s);
+        } catch (Exception e) {
+            return false;
+        }
+        return ip <= 255 && ip >= 0;
+    }
+}

B_FindNumber.java

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+package aoj.contest1399;
+
+public class B_FindNumber {
+    public static void main(String[] args) {
+        for (int n = 1; ; n++) {
+            if (n % 8 != 1) continue;
+            if (n / 8 % 8 != 1) continue;
+            if (n / 64 % 8 != 7) continue;
+            int a = n / 64 / 8;
+            if (n % 17 != 4) continue;
+            if (n / 17 % 17 != 15) continue;
+            int b = n / 17 / 17;
+            if (b != 2 * a) continue;
+            System.out.println(n);
+            break;
+        }
+    }
+}

C_Primer.java

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+package aoj.contest1399;
+
+import java.io.PrintWriter;
+import java.util.Scanner;
+ 
+public class C_Primer {
+    static Scanner cin = new Scanner(System.in);
+    static PrintWriter cout = new PrintWriter(System.out);
+    static {
+    }
+ 
+    public static void main(String[] args) {
+        cout.println(cin.nextBigInteger().isProbablePrime(20)?1:0);
+        cin.close();
+        cout.close();
+    }
+}

D_SumOdd.java

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+package aoj.contest1399;
+
+import java.util.Scanner;
+ 
+public class D_SumOdd {
+    public static void main(String[] args) {
+        Scanner cin = new Scanner(System.in);
+        int n = cin.nextInt();        
+        if (n % 2 == 0) --n;
+        n = (n + 1) / 2;
+        System.out.println(n * n);
+    }
+}

E_TwinNumbers.java

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+package aoj.contest1399;
+
+import java.io.PrintWriter;
+import java.util.Scanner;
+ 
+public class E_TwinNumbers {
+    static Scanner cin = new Scanner(System.in);
+    static PrintWriter cout = new PrintWriter(System.out);
+ 
+    public static void main(String[] args) {
+        for (int T = cin.nextInt(); T-- > 0; ) {
+            int n = cin.nextInt(), m = cin.nextInt();
+            if (f(n) == m && f(m) == n)
+                cout.println("YES");
+            else
+                cout.println("NO");
+        }
+        cout.close();
+        cin.close();
+    }
+ 
+    private static int f(int n) {
+        int tot = 1,c;
+        for (c = 2; c * c < n; c++)
+            if (n % c == 0) tot += c + n / c;
+        if (n % c == 0)
+            tot += c;
+        return tot;
+    }
+ 
+ 
+}