Computer Science 523
Advanced Programming
Summer 2014, The College of Saint Rose
Sum1ToNBetter BlueJ Project
Click here to download a BlueJ project for Sum1ToNBetter.
Sum1ToNBetter Source Code
The Java source code for Sum1ToNBetter is below. Click on a file name to download it.
/*
* Example Sum1ToN - a method that returns the sum of the integer
* values from 1 to a given number -- now using a more efficient
* formula for the computation
*
* Jim Teresco, The College of Saint Rose, CSC 202, Fall 2012
*
* $Id: Sum1ToNBetter.java 1995 2012-11-27 01:39:43Z terescoj $
*/
public class Sum1ToNBetter {
// our method looks like the ones we had before, except this
// one now returns an int
public static int sumNumbersTo(int limit) {
// we just compute this using our mathematical formula
return limit * (limit+1) / 2;
}
public static void main(String[] args) {
// for this example, we will just print out a few of these sums
int firstSum = sumNumbersTo(10);
System.out.println("The sum of the numbers 1-10 is " + firstSum);
int secondSum = sumNumbersTo(82);
System.out.println("The sum of the numbers 1-82 is " + secondSum);
int thirdSum = sumNumbersTo(96352);
System.out.println("The sum of the numbers 1-96352 is " + thirdSum);
// or we can use this within a loop
for (int number = 1; number <= 9; number++) {
// and we can use the value as part of a printout or any other expression
// if we do not want or need to save it in a variable
System.out.println("The sum of the numbers 1-" + number +
" is " + sumNumbersTo(number));
}
}
}