結果
問題 |
No.731 等差数列がだいすき
|
ユーザー |
![]() |
提出日時 | 2020-10-04 12:38:06 |
言語 | Java (openjdk 23) |
結果 |
AC
|
実行時間 | 257 ms / 1,500 ms |
コード長 | 2,694 bytes |
コンパイル時間 | 2,748 ms |
コンパイル使用メモリ | 79,116 KB |
実行使用メモリ | 49,280 KB |
最終ジャッジ日時 | 2024-07-19 08:26:33 |
合計ジャッジ時間 | 8,080 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 18 |
ソースコード
import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.NoSuchElementException; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); //FastScanner scanner=new FastScanner(); PrintWriter out = new PrintWriter(System.out); int n=scanner.nextInt(); double[] a=new double[n]; for(int i=0; i<n; i++) { a[i]=scanner.nextDouble(); } double p1=(double)n; double q1=(double)n*(double)(n-1)/2; double r1=0; double p2=(double)n*(double)(n-1)/2; double q2=(double)n*(double)(n-1)*(double)(2*n-1)/6; double r2=0; for(int i=0; i<n; i++) { r1+=a[i]; r2+=a[i]*i; } double b1=(r2*q1-r1*q2)/(p2*q1-p1*q2); double d=(r2*p1-r1*p2)/(q2*p1-q1*p2); double c=0; for(int i=0; i<n; i++) { c+=(b1+d*i-a[i])*(b1+d*i-a[i]); } out.printf("%.7f %.7f\n", b1, d); out.printf("%.7f\n", c); out.close(); scanner.close(); } } class FastScanner { private final InputStream in = System.in; private final byte[] buffer = new byte[1024]; private int ptr = 0; private int buflen = 0; private boolean hasNextByte() { if (ptr < buflen) { return true; } else { ptr = 0; try { buflen = in.read(buffer); } catch (IOException e) { e.printStackTrace(); } if (buflen <= 0) { return false; } } return true; } private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1; } private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126; } public boolean hasNext() { while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte(); } public String next() { if (!hasNext()) throw new NoSuchElementException(); StringBuilder sb = new StringBuilder(); int b = readByte(); while (isPrintableChar(b)) { sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } public long nextLong() { if (!hasNext()) throw new NoSuchElementException(); long n = 0; boolean minus = false; int b = readByte(); if (b == '-') { minus = true; b = readByte(); } if (b < '0' || '9' < b) { throw new NumberFormatException(); } while (true) { if ('0' <= b && b <= '9') { n *= 10; n += b - '0'; } else if (b == -1 || !isPrintableChar(b)) { return minus ? -n : n; } else { throw new NumberFormatException(); } b = readByte(); } } public int nextInt() { long nl = nextLong(); if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException(); return (int) nl; } public double nextDouble() { return Double.parseDouble(next()); } }