Java program to programmatically find the sums of mathematical series

user_7833774 0
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I need to write a Java program that does the following - For each of the first ten positive integers, raise them all to power 1, then find that sum. Then raise them all to power 2, and find the sum. Then raise them to power 3, and then find the sum and so on and so forth and then just print out the sums. Basically,

11 + 21 + 31 + ... + 101 = sum1
12 + 22 + 32 + ... + 102 = sum2
13 + 23 + 33 + ... + 103 = sum3
14 + 24 + 34 + ... + 104 = sum4
15 + 25 + 35 + ... + 105 = sum5

and just print out the values of sum1 to sum5.
Here's what I've tried;

public static void main(String[] args) {

    for (double power=1;power<=5;power++)
    {
        for (double n=1;n<=10;n++)
        {
            double result = (Math.pow(n, power));
        if (n%10==0)
        {
            double sum=0;
            sum+=result;
            System.out.println(sum);
        }

    }
}
}
}


I do get five outputs, but not quite the desirable ones. It just prints out

10.0
100.0
1000.0
10000.0
100000.0


How do I fix this?

java
3 Answers

It's pretty easy when you use IntStream ranges:

public static void main(String[] args) {
    IntStream.range(1, 6) // second param is exclusive
             .map(power ->
                      IntStream.range(1, 11)
                               .map(n -> (int) Math.pow(n, power))
                               .sum())
             .forEach(System.out::println);
}

Output:

55
385
3025
25333
220825

The heavy lifting is done by this bit:

IntStream.range(1, 11)
    .map(n -> (int) Math.pow(n, power))
    .sum()

it loops over the ints from 1 to 10, raises each of them to the current power, and sums them up together. The outer stream just loops over the powers and pipes the output to System.out.println().

user_3428520

First you don't need if block in inner for loop which is ignoring the values other that 10 and second you just need variable in outer for to store the result

for (double power = 1; power <= 5; power++) {

        double sum = 0;
        for (double n = 1; n <= 10; n++) {
            double result = (Math.pow(n, power));
            sum=sum+result;

        }
        System.out.println(sum);
    }
user_99591520

public class Numrat {

public static void main(String [] args) {
    double sum=0;
    for(int power=1; power<6; power++) {

        for(int j= 1;j<11; j++) {
            double variable=(Math.pow(j, power));
            sum +=variable;


        }
        System.out.println(sum);
    }

}

}

user_122283810
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