C++ and Algorithmic Thinking for the Complete Beginner

Chapter 41 More with Files

41.1 Exercises of a General Nature with Files

Exercise 41.1-1 Calculating the Sum of 10 Numbers

Suppose there is a file named “f_data41.1-1.txt” that contains 10 3-digit integers (separated by a single space character). An example of the structure of the file is shown here.

131 500 122 152 127 191 111 290 156 161

Write a C++ program that calculates and displays their sum.

Solution

There are two approaches to iterate through the numbers of this file.

First approach

In this approach, a string variable named values gets the content of the whole line of the file. Then, the substr() method is used in a for-loop to split the content into individual three-digit numbers. These numbers are then converted to integers using ...