pre-release v2023.03.15

Author: gdut-yy

atcoder-beginner/src/main/java/c280/Abc280_e.java

@@ -1,30 +1,53 @@
 package c280;
 
+import java.nio.charset.StandardCharsets;
+import java.util.Scanner;
+
 public class Abc280_e {
     private static final int MOD = 998244353;
 
     public static void main(String[] args) {
-        // 281/100 (mod 998244353) = 229596204
-        System.out.println(281 * inv(100, MOD) % MOD);
+        Scanner scanner = new Scanner(System.in, StandardCharsets.UTF_8);
+        int n = scanner.nextInt();
+        int p = scanner.nextInt();
+        System.out.println(solve(n, p));
+    }
+
+    private static String solve(int n, int p) {
+        long inv = inv(100, MOD);
+        long x = 1, ans = 1;
+        for (int i = 0; i < n - 1; i++) {
+            x = (1 - x * p % MOD * inv % MOD + MOD) % MOD;
+            ans = (ans + x) % MOD;
+        }
+        return String.valueOf(ans);
     }
 
-    private static long inv(long a, long mod) {
-        return quickPow(a, mod - 2, mod);
+    static long inv(long a, long b) {
+        x = 0;
+        y = 0;
+        exgcd(a, b);
+        return (x + b) % b;
     }
 
-    private static long quickPow(long a, long b, long mod) {
-        long res = 1L;
-        while (b > 0) {
-            if ((b & 1) == 1) {
-                res = res * a % mod;
-            }
-            a = a * a % mod;
-            b >>= 1;
+    static long x, y;
+
+    static long exgcd(long a, long b) {
+        if (b == 0) {
+            x = 1;
+            y = 0;
+            return a;
         }
-        return res;
+        long d = exgcd(b, a % b);
+        long tmp = x;
+        x = y;
+        y = tmp - a / b * y;
+        return d;
     }
 }
 /*
 E - Critical Hit
 https://atcoder.jp/contests/abc280/tasks/abc280_e
+
+exgcd 求逆元
  */

atcoder-beginner/src/test/java/c280/Abc280eTests.java

@@ -0,0 +1,33 @@
+package c280;
+
+import base.AbstractOjTests;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+public class Abc280eTests extends AbstractOjTests {
+    public Abc280eTests() {
+        super("/c280/E/");
+    }
+
+    @Test
+    public void example1() throws IOException {
+        super.doSetSystemInOut(INPUT1);
+        Abc280_e.main(null);
+        super.doAssertion(OUTPUT1);
+    }
+
+    @Test
+    public void example2() throws IOException {
+        super.doSetSystemInOut(INPUT2);
+        Abc280_e.main(null);
+        super.doAssertion(OUTPUT2);
+    }
+
+    @Test
+    public void example3() throws IOException {
+        super.doSetSystemInOut(INPUT3);
+        Abc280_e.main(null);
+        super.doAssertion(OUTPUT3);
+    }
+}

atcoder-beginner/src/test/resources/c280/E/input1.txt

@@ -0,0 +1 @@
+3 10

atcoder-beginner/src/test/resources/c280/E/input2.txt

@@ -0,0 +1 @@
+5 100

atcoder-beginner/src/test/resources/c280/E/input3.txt

@@ -0,0 +1 @@
+280 59

atcoder-beginner/src/test/resources/c280/E/output1.txt

@@ -0,0 +1 @@
+229596204

atcoder-beginner/src/test/resources/c280/E/output2.txt

@@ -0,0 +1 @@
+3

atcoder-beginner/src/test/resources/c280/E/output3.txt

@@ -0,0 +1 @@
+567484387