I am working on a program that takes an integer and finds the number of combinations of consecutive sums that the integer has:
The number 13 can be expressed as a sum of consecutive positive integers 6 + 7. Fourteen can be expressed as 2 + 3 + 4 + 5, also a sum of consecutive positive integers. Some numbers can be expressed as a sum of consecutive positive integers in more than one way. For example, 25 is 12 + 13 and is also 3 + 4 + 5 + 6 + 7.
I researched and read that it's the number of odd factors minus one. So I wrote a program that finds the number of odd factors and my answer is still wrong in certain cases. Any insight?
Code seems to work fine but there is a crash due to Timeout which is probably due to optimization error.
The constraints for possible input size is 1 to 10^(12)
The code below is copied from alfasin's answer below:
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
static long consecutive(long num) {
while (num % 2 == 0) num /= 2;
return consecutiveHelper(num);
}
public static long consecutiveHelper(long num) {
return LongStream.rangeClosed(3, (num / 2)).parallel().filter(x -> x % 2 != 0).map(fn -> (num % fn == 0) ? 1 : 0).sum();
}
public static void main(String[] args) throws IOException {
Scanner in = new Scanner(System.in);
final String fileName = System.getenv("OUTPUT_PATH");
BufferedWriter bw = null;
if (fileName != null) {
bw = new BufferedWriter(new FileWriter(fileName));
}
else {
bw = new BufferedWriter(new OutputStreamWriter(System.out));
}
int res;
long num;
num = Long.parseLong(in.nextLine().trim());
res = consecutive(num);
bw.write(String.valueOf(res));
bw.newLine();
bw.close();
}
}
This is what i currently have
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