結果
| 問題 | No.754 畳み込みの和 | 
| コンテスト | |
| ユーザー |  | 
| 提出日時 | 2019-04-28 12:44:17 | 
| 言語 | Java (openjdk 23) | 
| 結果 | 
                                AC
                                 
                             | 
| 実行時間 | 226 ms / 5,000 ms | 
| コード長 | 4,348 bytes | 
| コンパイル時間 | 4,097 ms | 
| コンパイル使用メモリ | 78,244 KB | 
| 実行使用メモリ | 43,208 KB | 
| 最終ジャッジ日時 | 2024-12-15 23:29:01 | 
| 合計ジャッジ時間 | 6,300 ms | 
| ジャッジサーバーID (参考情報) | judge5 / judge2 | 
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| ファイルパターン | 結果 | 
|---|---|
| other | AC * 3 | 
ソースコード
import java.io.*;
import java.util.NoSuchElementException;
public class Main_yukicoder754 {
	private static Scanner sc;
	private static Printer pr;
	private static void solve() {
		final int MOD = 1_000_000_007;
		int n = sc.nextInt();
		int[] a = new int[n + 1];
		int[] b = new int[n + 1];
		for (int i = 0; i <= n; i++) {
			a[i] = sc.nextInt();
		}
		for (int i = 0; i <= n; i++) {
			b[i] = sc.nextInt();
		}
		int[] cumsum = new int[n + 2];
		for (int i = 0; i <= n; i++) {
			cumsum[i + 1] = cumsum[i] + b[i];
			cumsum[i + 1] %= MOD;
		}
		long ans = 0;
		for (int i = 0; i <= n; i++) {
			ans += (long)a[i] * cumsum[n - i + 1];
			ans %= MOD;
		}
		pr.println(ans);
	}
	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);
			
		solve();
			
		pr.close();
		sc.close();
	}
	static class Scanner {
		BufferedReader br;
		Scanner (InputStream in) {
			br = new BufferedReader(new InputStreamReader(in));
		}
		private boolean isPrintable(int ch) {
			return ch >= '!' && ch <= '~';
		}
		private boolean isCRLF(int ch) {
			return ch == '\n' || ch == '\r' || ch == -1;
		}
		private int nextPrintable() {
			try {
				int ch;
				while (!isPrintable(ch = br.read())) {
					if (ch == -1) {
						throw new NoSuchElementException();
					}
				}
				return ch;
			} catch (IOException e) {
				throw new NoSuchElementException();
			}
		}
		String next() {
			try {
				int ch = nextPrintable();
				StringBuilder sb = new StringBuilder();
				do {
					sb.appendCodePoint(ch);
				} while (isPrintable(ch = br.read()));
				return sb.toString();
			} catch (IOException e) {
				throw new NoSuchElementException();
			}
		}
		int nextInt() {
			try {
				// parseInt from Integer.parseInt()
				boolean negative = false;
				int res = 0;
				int limit = -Integer.MAX_VALUE;
				int radix = 10;
				int fc = nextPrintable();
				if (fc < '0') {
					if (fc == '-') {
						negative = true;
						limit = Integer.MIN_VALUE;
					} else if (fc != '+') {
						throw new NumberFormatException();
					}
					fc = br.read();
				}
				int multmin = limit / radix;
				int ch = fc;
				do {
					int digit = ch - '0';
					if (digit < 0 || digit >= radix) {
						throw new NumberFormatException();
					}
					if (res < multmin) {
						throw new NumberFormatException();
					}
					res *= radix;
					if (res < limit + digit) {
						throw new NumberFormatException();
					}
					res -= digit;
				} while (isPrintable(ch = br.read()));
				return negative ? res : -res;
			} catch (IOException e) {
				throw new NoSuchElementException();
			}
		}
		long nextLong() {
			try {
				// parseLong from Long.parseLong()
				boolean negative = false;
				long res = 0;
				long limit = -Long.MAX_VALUE;
				int radix = 10;
				int fc = nextPrintable();
				if (fc < '0') {
					if (fc == '-') {
						negative = true;
						limit = Long.MIN_VALUE;
					} else if (fc != '+') {
						throw new NumberFormatException();
					}
					fc = br.read();
				}
				long multmin = limit / radix;
				int ch = fc;
				do {
					int digit = ch - '0';
					if (digit < 0 || digit >= radix) {
						throw new NumberFormatException();
					}
					if (res < multmin) {
						throw new NumberFormatException();
					}
					res *= radix;
					if (res < limit + digit) {
						throw new NumberFormatException();
					}
					res -= digit;
				} while (isPrintable(ch = br.read()));
				return negative ? res : -res;
			} catch (IOException e) {
				throw new NoSuchElementException();
			}
		}
		float nextFloat() {
			return Float.parseFloat(next());
		}
		double nextDouble() {
			return Double.parseDouble(next());
		}
		String nextLine() {
			try {
				int ch;
				while (isCRLF(ch = br.read())) {
					if (ch == -1) {
						throw new NoSuchElementException();
					}
				}
				StringBuilder sb = new StringBuilder();
				do {
					sb.appendCodePoint(ch);
				} while (!isCRLF(ch = br.read()));
				return sb.toString();
			} catch (IOException e) {
				throw new NoSuchElementException();
			}
		}
		void close() {
			try {
				br.close();
			} catch (IOException e) {
//				throw new NoSuchElementException();
			}
		}
	}
	static class Printer extends PrintWriter {
		Printer(OutputStream out) {
			super(out);
		}
	}
}
            
            
            
        