Competitive Programming #19: [Check if array contains contiguous integers with duplicates allowed]

Given an array of n integers(duplicates allowed). Print “Yes” if it is a set of contiguous integers else print “No”.

INPUT: The first line consists of an integer T i.e. the number of test cases. First line of each test case consists of an integer n, denoting the size of array. Next line consists of n spaced integers, denoting elements of array.

OUTPUT:  Print “Yes” if it is a set of contiguous integers else print “No”.

CONSTRAINTS:
1<=T<=100
1<=n<100000 br=""> a[i]<=10⁵
 Example:
 2
8
5  2  3  6  4  4  6  6
7
10  14  10  12  12  13  15
Output :
 Yes
 No
Explanation:
Test Case 1 : The elements  of array form a contiguous set of integers which is {2, 3, 4, 5, 6} so the output is Yes.
Test Case 2: We are unable to form contiguous set of integers using elements of array.

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Solution: 
 
Lets take a example like this one
8
1 2 3 4 6 7 8 9
in our array contg_numbers we have
                               0     1     2      3    4      5      6    7     8     9
contg_numbers={false,true,true,true,true,false,true,true,true,true,.....}
Variable 'flag' is until it find TRUE value...and its flow until it find FALSE.'.flag1' is if find another TRUE then 'flag'=true
in our example we have
if contg_numbers[0]=true AND flag=false -> (TRUE) ->  flag=true
i=1;
if contg_numbers[1]=true AND flag=false -> (NO)-> /
else if contg_numbers[1]=false AND flag=true -> (NO) ->
else if contg_numbers[1]=true  AND flag1=true ->NO ->
until 5 then  we have
ELSE IF congt_numbers[5]=false AND flag=true  ->(YES) ->flag1=true
i=6;
ELSE IF contg_numbers[6]=true AND flag1=true -> (YES) -> flag=false; break;
and Output will be "No"