FUNNUMS  FUN WITH LETTERS
Mr. Bean’s uncle gifted him 15 English letter toys from 'a' to 'o'. As Mr. Bean is a joker, no one was willing to play with him. So he sat on the floor and arranged these toys in ascending order i.e. “abcdefghijklmno”. Then he figured out the next greatest string in lexicographic order that can be formed by rearranging the toys is “abcdefghijklmon”. Now he is learning programming and wants to write a program to solve the following problem: Given a string S which can be formed by rearranging the toys, find the Nth greater string in lexicographic order. You can safely assume that such a string always exists.
Input Specification:
The first line contains a natural number T denoting the number of test cases. Next T lines contain the description of T test cases, each with string S and value N.
Output Specification:
For each test case print the answer in a separate line.
Input Constraints:
1<=t<=1000
2<=S.length()<=15
'a'<=S[i]<='a'+S.length()1
All letters in S are unique.
Sample Input:
3
abdc 2
adcb 3
badc 7
Sample Output:
acdb
bcad
cbad
hide comments
nadstratosfer:
20180130 23:28:09
Bugged me for a few days and took quite a while to figure out when I finally sat down to it. Ended up with a strong solution that I'm pretty sure will pay off in the future also. Great problem, the "fun" in the title is no clickbait. 

be1035016:
20180117 19:24:52
1 go ac:credit goes to CnC:) 

Akshat Mathur:
20150805 16:56:41
Finally AC :) 

Saurabh_P:
20131225 23:53:02
getting tle.... dont get it 

Abhinav:
20131217 12:57:29
use long long int ...I got 4 WAs bcoz of that 

Kartik Khare:
20131217 12:57:29
just can't figure out why am i getting wrong answer. 

BLANKRK:
20131217 12:57:29
m gettin tle again n again.... whts the problm 

Aradhya:
20131217 12:57:29
50th user \m/ 

Aradhya:
20131217 12:57:29
ohh my god.... got loads of wrong answers just because of a silly mistake :P :P.. btw awesome problem ;) 

Federico LebrÃ³n:
20131217 12:57:29
I'm not sure I follow. If I have the letters abdc, of all the possible permutations of those letters, the 2nd greatest one lexicographically is dcab (the largest is dcba). Why is the correct answer acdb? And why does it matter that the input is permuted? The lexicographical permutations will be the same (as will their order), regardless of the initial permutation of S.

Added by:  cegprakash 
Date:  20130224 
Time limit:  2s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 