## Project Euler & HackerRank Problem 13 Solution

##### Large sum

by {BetaProjects} | MAY 17, 2009 | Project Euler & HackerRank### Project Euler Problem 13 Statement

Work out the first ten digits of the sum of the following one-hundred 50-digit numbers.

37107287533902102798797998220837590246510135740250 46376937677490009712648124896970078050417018260538 … {data continues}

### Solution

Summing a set of 50–digit numbers uses Python’s intrinsic arbitrary–precision integers and arithmetic.

The numbers to add are saved to a file named *pe13.txt*. This keeps the data and the program separate and the process easy to comprehend.

The file is read as strings and converted to a list of integers using the `map`

function with `open`

as the iterator and `int`

as the application function:

`total = sum(map(int, open('pe13.txt')))`

.

After the end of the file is reached the list is fed to the `sum`

function which adds the integers together:

`total = sum(map(int, open('pe13.txt')))`

.

Finally, the integer sum, `total`

, is converted to a string and truncated to the top 10 digits for a solution.

`str(total)[:10]`

#### HackerRank version

### Python Source Code

### Last Word

The data file, *pe13.txt*, is available on repl.it page by clicking the files icon in the top left corner.