Figure 1

The flowchart for the generation of a HASH value. This function will iterate through each character of the input, and the returned value differs according to the type of the character: 1. an alphabetical character, its position comparing to ‘a’ (if it is lowercase) or ‘A’ (if it is uppercase) will be returned (the positions of ‘a’ and ‘A’ are set to 0); 2. a digit, the value of itself will be returned; 3. an underline, the value will be set to 36. If it does not belong to any shown above, the function will do nothing and continue to calculate the next character. At the end of each iteration, the value of one character will be added to the sum that is multiplied by 40 to get a new sum.