Problem 022

Project Euler

Names scores

Problem 22

Using names.txt (right click and ‘Save Link/Target As…’), a 46K text file containing over five-thousand first names, begin by sorting it into alphabetical order. Then working out the alphabetical value for each name, multiply this value by its alphabetical position in the list to obtain a name score.

For example, when the list is sorted into alphabetical order, COLIN, which is worth 3 + 15 + 12 + 9 + 14 = 53, is the 938th name in the list. So, COLIN would obtain a score of 938 × 53 = 49714.

What is the total of all the name scores in the file?

Since the score for each name is relative to each other, the list must be sorted to get the positions. Most library has efficient sorting function and make this problem extremely easy. To get more practice about coding (after all, project euler is a coding / math exercise), implement a sorting and searching function won’t take too much longer to do. There are many ways to code a sorting function, one way is to build a binary tree from the list. Assume the list of names has been randomize (and it looks like it is), the binary tree will be quite balance and efficient. Once built, the sum can be calculate by doing an in-order traversal.


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