mergeSegment = function(segment1, segment2) {
	var merged = [];
	
	if(segment1[0] <= segment2[0]) {
		if(segment1[1] < segment2[0]) {
			merged = [segment1, segment2];
		}
		else {
			if(segment1[1] >= segment2[1])
				merged = [segment1];
			else 
				merged = [[segment1[0], segment2[1]]];
		}
	}
	else {
		if(segment2[1] < segment1[0]) {
			merged = [segment2, segment1];
		}
		else {
			if(segment2[1] >= segment1[1])
				merged = [segment2];
			else 
				merged = [[segment2[0], segment1[1]]];
		}
	}
	return merged;
}

compareSegment = function(segment1, segment2) {
	// inclusi o coincidenti
	if((segment1[0] >= segment2[0]) && (segment1[1] <= segment2[1]))
		return 0;
	if((segment1[0] <= segment2[0]) && (segment1[1] >= segment2[1]))
		return 0;
	// esterni
	if((segment1[1] < segment2[0]) || ((segment1[0] > segment2[1])))
		return 1;
	// intersecanti
	return -1;
}

compareSegments = function(s1, s2) {
	return (s1[0] - s2[0]);
}

cleanSegmentList = function(list) {
	var cleaned = [];
	for(var i=0; i<list.length; i++) {
		if(cleaned.length == 0)
			cleaned[cleaned.length] = list[i];
		else {
			var found = false;			
			for(var j=0; j<cleaned.length; j++) {
				if(compareSegment(cleaned[j], list[i]) == 0) {
					if(cleaned[j][0] > list[i][0])	
						cleaned[j] = list[i];
					found = true;
					break;
				}
				if(compareSegment(cleaned[j], list[i]) < 0) {
					if(cleaned[j][0] <= list[i][0]) 
						cleaned[j] = [cleaned[j][0], list[i][1]];
					else
						cleaned[j] = [list[i][0], cleaned[j][1]];
					found = true;
				}
			}
			if(!found) cleaned[cleaned.length] = list[i];
		}
	 }
	return cleaned;
}

compareSegmentList = function(list1, list2) {
	if(list1.length != list2.length)
		return false;
	for(var i=0; i<list1.length; i++)
		if((list1[i][0] != list2[i][0]) || (list1[i][1] != list2[i][1]))
			return false;
	return true;
}

/**
 * mergeAll: merge indices
 * parameters: indices = Array of Array of indices (index = [start, end])
 * Example: indices = [[[1,2], [4,5]], [[0,5], [7,11]]];
 */

mergeAll = function(indices) {
	console.log("---mergeAll indices.length=" + indices.length);
	var m = [];
	for(var i=0; i<indices[0].length; i++) {
	 	for(var j=1; j<indices.length; j++) {
	 		for(var k=0; k<indices[j].length; k++) {
	 			var res = mergeSegment(indices[0][i], indices[j][k]);
	 			for(var u=0; u<res.length; u++) 
	 				m[m.length] = res[u];
	 		}
	 	}
	}
/*	
	var end = false;
	var counter = 1;
	while(!end) {
		var old = m.slice();
		m = cleanSegmentList(m);
		//console.log(m);
		end = compareSegmentList(old, m);
		counter++;
		if(counter == 100)
			end = true;
	}
	return m.sort(compareSegments);*/
	
	m = m.sort(compareSegments);
	var m2 = [];
	var current = m[0];
	for(var i=0; i<m.length; i++) {
		var cfr = compareSegment(current, m[i]);
		switch(cfr) {
		case 0:
		case -1:
			current = mergeSegment(current, m[i])[0];
			break;
		default:
			var s = mergeSegment(current, m[i]);
			m2[m2.length] = s[0];
			current = s[1];
			break;
		}
	}
	
	if((current[0] != m2[m2.length-1][0]) || (current[1] != m2[m2.length-1][1]))
		m2[m2.length] = current;	
	return m2;
}