1. modified the identifiers and used the suitable identifiers for the variables
2. leave the loop when a key is match and found to increase the speed of searching in this stage of development
3. return the key number if founded, return 0 if found nothing
Made 2 changes to optimize the match results:
1. use a loop to find the next digit of wordbank element and compare with outStr's digit
2. this part need to be optimize with the calculation of the number of occurance of word's probabilities
