JOIN

 Problem Statement

Problem Statement for RangeEncoding

### Problem Statement

You are given a int[] arr that contains a set of positive integers. The elements in arr are all distinct and they are given in increasing order.

A range is a finite set of consecutive integers. Formally, for any two positive integers a ≤ b the range [a,b] is defined to be the set of all integers that lie between a and b, inclusive. For example, [3,3] = {3} and [4,7] = {4,5,6,7}.

You want to represent the set given in arr as a union of some ranges. Return the minimum number of ranges you need.

### Definition

 Class: RangeEncoding Method: minRanges Parameters: int[] Returns: int Method signature: int minRanges(int[] arr) (be sure your method is public)

### Constraints

-arr will have between 1 and 50 elements, inclusive.
-Each element of arr will be between 1 and 50.
-The elements in arr will be in strictly increasing order.

### Examples

0)

 `{1,2,3,4,5,6,7,8,9,10} `
`Returns: 1`
 We can represent this set as a single range [1,10].
1)

 `{1,6,10,20,32,49}`
`Returns: 6`
 In this case we have to use 6 different ranges, each containing just a single number.
2)

 `{2,4,5,6,8,9,10,11,12,15}`
`Returns: 4`
 This set of integers can be represented as the union of four ranges: [2,2], [4,6], [8,12], and [15,15].
3)

 `{2,3,5,7,11,13,17,19,23,29,31,37,41,43,47}`
`Returns: 14`
4)

 `{10,11,12,13,14,15,20,21,22,23,25,27,28,29,30,31,32,33}`
`Returns: 4`
5)

 `{33}`
`Returns: 1`

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This problem was used for:
Single Round Match 714 Round 1 - Division II, Level One
2017 TCO Algorithm Russia Regional Round - Division I, Level One