結果

問題 No.978 Fibonacci Convolution Easy
ユーザー OlandOland
提出日時 2020-02-01 07:24:34
言語 Java21
(openjdk 21)
結果
AC  
実行時間 201 ms / 2,000 ms
コード長 7,323 bytes
コンパイル時間 2,618 ms
コンパイル使用メモリ 78,816 KB
実行使用メモリ 55,184 KB
最終ジャッジ日時 2023-10-19 01:09:14
合計ジャッジ時間 6,089 ms
ジャッジサーバーID
（参考情報） 		judge14 / judge13
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 63 ms
52,572 KB
testcase_01 AC 126 ms
54,648 KB
testcase_02 AC 101 ms
54,672 KB
testcase_03 AC 195 ms
54,676 KB
testcase_04 AC 108 ms
54,652 KB
testcase_05 AC 82 ms
54,660 KB
testcase_06 AC 119 ms
55,184 KB
testcase_07 AC 154 ms
54,656 KB
testcase_08 AC 130 ms
54,692 KB
testcase_09 AC 164 ms
54,680 KB
testcase_10 AC 200 ms
54,672 KB
testcase_11 AC 110 ms
54,664 KB
testcase_12 AC 71 ms
53,004 KB
testcase_13 AC 120 ms
54,656 KB
testcase_14 AC 89 ms
52,632 KB
testcase_15 AC 124 ms
52,656 KB
testcase_16 AC 200 ms
54,680 KB
testcase_17 AC 201 ms
54,676 KB
testcase_18 AC 57 ms
52,596 KB
testcase_19 AC 57 ms
53,688 KB
testcase_20 AC 56 ms
53,680 KB
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ソースコード

diff # 

import java.util.*;
import java.io.*;

@SuppressWarnings("unused")
public class Main {
    FastScanner in;
    PrintWriter out;
    int MOD = (int)1e9+7;
    long ceil(long a, long b){return (a + b - 1) / b;}
    long gcd(long a, long b){return b == 0 ? a : gcd(b, a % b);}
    long lcm(long a, long b){return a / gcd(a, b) * b;}
    
    void solve(){
        int N = in.nextInt(), p = in.nextInt();
        if(N == 1){
            out.println("0");
            return;
        }
        long sum = 1, sum2 = 1;
        long[] a = new long[]{0, 1, 0};
        for(int i = 2; i < N; i++){
            a[i % 3] = (p * a[(i + 2) % 3] % MOD + a[(i + 1) % 3]) % MOD;
            sum = (sum + a[i % 3]) % MOD;
            sum2 = (sum2 + a[i % 3] * a[i % 3] % MOD) % MOD;
        }
        long ans = (sum * sum % MOD + sum2) % MOD * modMultiInv(2, MOD) % MOD;
        out.println(ans);
    }
    
    //n^-1 % MOD をlog(MOD)で計算
    public static long modMultiInv(long a, int mod){
        return modPow(a, mod-2, mod);
    }
    
    //a^b % MOD をlog(b)で計算
    public static long modPow(long a, long b, int mod){
        long res = 1;
        while(b > 0){
            if((b & 1) == 1) res = (res * a) % mod;
            a = (a * a) % mod;
            b = b >> 1;
        }
        return res;
    }
    
    public static void main(String[] args) {
        new Main().m();
    }
    
    private void m() {
        in = new FastScanner(System.in);
        out = new PrintWriter(System.out);
        /*
        try {
            String path = "input.txt";
            out = new PrintWriter(new BufferedWriter(new FileWriter(new File(path))));
        }catch (IOException e){
            e.printStackTrace();
        }
        */
        solve();
        out.flush();
        in.close();
        out.close();
    }
    
    static class FastScanner {
        private Reader input;
        
        public FastScanner() {this(System.in);}
        public FastScanner(InputStream stream) {this.input = new BufferedReader(new InputStreamReader(stream));}
        public void close() {
            try {
                this.input.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        
        public int nextInt() {return (int) nextLong();}
        
        public long nextLong() {
            try {
                int sign = 1;
                int b = input.read();
                while ((b < '0' || '9' < b) && b != '-' && b != '+') {
                    b = input.read();
                }
                if (b == '-') {
                    sign = -1;
                    b = input.read();
                } else if (b == '+') {
                    b = input.read();
                }
                long ret = b - '0';
                while (true) {
                    b = input.read();
                    if (b < '0' || '9' < b) return ret * sign;
                    ret *= 10;
                    ret += b - '0';
                }
            } catch (IOException e) {
                e.printStackTrace();
                return -1;
            }
        }
        
        public double nextDouble() {
            try {
                double sign = 1;
                int b = input.read();
                while ((b < '0' || '9' < b) && b != '-' && b != '+') {
                    b = input.read();
                }
                if (b == '-') {
                    sign = -1;
                    b = input.read();
                } else if (b == '+') {
                    b = input.read();
                }
                double ret = b - '0';
                while (true) {
                    b = input.read();
                    if (b < '0' || '9' < b) break;
                    ret *= 10;
                    ret += b - '0';
                }
                if (b != '.') return sign * ret;
                double div = 1;
                b = input.read();
                while ('0' <= b && b <= '9') {
                    ret *= 10;
                    ret += b - '0';
                    div *= 10;
                    b = input.read();
                }
                return sign * ret / div;
            } catch (IOException e) {
                e.printStackTrace();
                return Double.NaN;
            }
        }
        
        public char nextChar() {
            try {
                int b = input.read();
                while (Character.isWhitespace(b)) {
                    b = input.read();
                }
                return (char) b;
            } catch (IOException e) {
                e.printStackTrace();
                return 0;
            }
        }
        
        public String nextStr() {
            try {
                StringBuilder sb = new StringBuilder();
                int b = input.read();
                while (Character.isWhitespace(b)) {
                    b = input.read();
                }
                while (b != -1 && !Character.isWhitespace(b)) {
                    sb.append((char) b);
                    b = input.read();
                }
                return sb.toString();
            } catch (IOException e) {
                e.printStackTrace();
                return "";
            }
        }
        
        public String nextLine() {
            try {
                StringBuilder sb = new StringBuilder();
                int b = input.read();
                while (b != -1 && b != '\n') {
                    sb.append((char) b);
                    b = input.read();
                }
                return sb.toString();
            } catch (IOException e) {
                e.printStackTrace();
                return "";
            }
        }
        
        public int[] nextIntArray(int n) {
            int[] res = new int[n];
            for (int i = 0; i < n; i++) {
                res[i] = nextInt();
            }
            return res;
        }
        
        public int[] nextIntArrayDec(int n) {
            int[] res = new int[n];
            for (int i = 0; i < n; i++) {
                res[i] = nextInt() - 1;
            }
            return res;
        }
        
        public int[] nextIntArray1Index(int n) {
            int[] res = new int[n + 1];
            for (int i = 0; i < n; i++) {
                res[i + 1] = nextInt();
            }
            return res;
        }
        
        public long[] nextLongArray(int n) {
            long[] res = new long[n];
            for (int i = 0; i < n; i++) {
                res[i] = nextLong();
            }
            return res;
        }
        
        public long[] nextLongArrayDec(int n) {
            long[] res = new long[n];
            for (int i = 0; i < n; i++) {
                res[i] = nextLong() - 1;
            }
            return res;
        }
        
        public long[] nextLongArray1Index(int n) {
            long[] res = new long[n + 1];
            for (int i = 0; i < n; i++) {
                res[i + 1] = nextLong();
            }
            return res;
        }
        
        public double[] nextDoubleArray(int n) {
            double[] res = new double[n];
            for (int i = 0; i < n; i++) {
                res[i] = nextDouble();
            }
            return res;
        }
    }
}
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