Authors:
Stuart Reges, Marty Stepp
Chapter:
Arraylists
Exercise:
Exercises
Question:9 | ISBN:9780136091813 | Edition: 2
Question
Write a method called rangeBetweenZeroes that takes as a parameter an ArrayList of integers and returns the number of indexes apart the two furthest occurrences of the number 0 are. For example, if the list stores the values (7, 2, 0, 0, 4, 0, 9, 0, 6, 4, 8) when the method is called, it should return 6, because the occurrences of 0 that are furthest apart are at indexes 2 and 7, and the range 2 through 7 has six elements. If only one 0 occurs in the list, your method should return 1 . If no 0 s occur, your method should return 0.
Answer
Implementation of rangeBetweenZeroes method:
public static int rangeBetweenZeroes(ArrayList intList)
{
boolean found = false;
int minIndex = 0;
int maxIndex = 0;
for(int i = 0; i < intList.size(); i++)
{
if(intList.get(i) == 0 && !found)
{
found = true;
minIndex = i;
}
if(intList.get(i) == 0 && found)
{
maxIndex = i;
}
}
if(found)
return (maxIndex - minIndex + 1);
else
return 0;
}