Using C++

Please explain as I am very confused.

Exercise 3.14: Read some text into a vector, storing each word in the input as an element in the vector. Transform each word into uppercase letters. Print the trans- formed elements from the vector, printing eight words to a line. Exercise 3.18: Write a program to create a vector with 10 elements. Using an iterator, assign each element a value that is twice its current value. Exercise 3.19: Test your previous program by printing the vector. Exercise 3.20: Explain which iterator you used in the previous programs, and why Exercise 3.22: What happens if we compute mid as follows: (VI . begin ( ) vi. end ( ) ) / 2 ; vector int : terator mid- +