Question

我需要做这个公式：

=（A1 / B1）+（A2 / B2）+（A3 / B3）等到第356行，我怎么能以更短的方式做到？

Answer 1

使用：

    import java.math.*;
    import java.io.*;
    public class FastFibonacci
    {
    private static BigInteger[] answers; 

        private static BigInteger one;
    private static BigInteger zero;

    private static BufferedReader stdin = new BufferedReader( new InputStreamReader( System.in ) );

    public static BigInteger fastFibonacci(int n)
    {
        if((n == 1) || (n == 2))
                        return answers[0];

                if(answers[n-1].compareTo(zero) != 0)
                        return answers[n-1];

        if(answers[n-2].compareTo(zero) == 0)
                    answers[n-2] = fastFibonacci(n-1);

        if(answers[n-3].compareTo(zero) == 0)
                    answers[n-3] = fastFibonacci(n-2);

                return answers[n-2].add(answers[n-3]);
    }

        public static void main(String[] args)
        {

                int n;
        long time, newTime;
        BigInteger answer;

                System.out.println("Type a positive integer." );
                try{
                       String input = stdin.readLine();
                        n = Integer.parseInt( input );

            zero = new BigInteger("0");
            one = new BigInteger("1");

            answers = new BigInteger[n];
            answers[0] = new BigInteger("1");
            answers[1] = new BigInteger("1");
            for(int i = 2; i < n; i++)
                answers[i] = new BigInteger("0");

                        time = System.currentTimeMillis();
                        answer = fastFibonacci(n);
                        newTime = System.currentTimeMillis();

                        System.out.println("The "+n+"th Fibonacci number is "+ answer);
                        System.out.println("It took " + (newTime-time) + " milliseconds to compute it.");

                }
                catch(java.io.IOException e)
                {
                        System.out.println(e);
                }



    }

}

这是一个数组公式。使用 Ctrl 确认 - Shift - 输入。

编辑：添加另一列：

=SUM(A1:A356/B1:B356)

同样是一个数组公式所以 Ctrl - Shift - Enter

Answer 2

作为非数组公式

=SUMPRODUCT(A1:A356,1/B1:B356)

高效的总和方法

2 个答案: