Code to determine overlaps in set of data ranges

gistfile1.java

/**

Problem: Given a set of data ranges (i.e. 2-7, 5-9, 10-20), write a function to determine if there is any overlap within the set. 
Write test cases. Which data structure would be best to represent the intervals.

Solution: I would prefer to use an array of size 2N and then iterate over it. Another 
way is to work up using interval tree's but I think that may be an overkill considering 
it used to check overlaps in multiple ranges and points.

*/

int[] array = new int[];

array[0] = 2;
array[1] = 7;
array[2] = 5;
array[3] = 9;
.
.
.
.
array[2n] = <some value>;

for(int i = 0; i < 2n; i += 2) {
        for(int j = i + 2; j <2 n; j += 2) {

		if(array[j] >= array[i] && array[j] <= array[i+1]) {
			// the starting element is between the range
			// there is an overlap
		} else if(array[j+1] >= array[i] && array[j+1] <= array[i+1]) {
			// the ending element is between the range
			// there is an overlap
		}
	}
}