c++学习笔记4：如何写好注释

// cout and endl live in the iostream library
std::cout << "Hello world!" << std::endl;

/* This is a multi-line comment.
 * the matching asterisks to the left
 * can make this easier to read
 */

.At the library, program, or function level, describe what
.Inside the library, program, or function, describe how
.At the statement level, describe why

// This program calculate the student‘s final grade based on his test and homework scores.

/* To calculate the final grade, we sum all the weighted midterm and homework scores
    and then divide by the number of scores to assign a percentage.  This percentage is
    used to calculate a letter grade. 
*/
// To generate a random item, we‘re going to do the following:
// 1) Put all of the items of the desired rarity on a list
// 2) Calculate a probability for each item based on level and weight factor
// 3) Choose a random number
// 4) Figure out which item that 

// We need to divide items by 2 here because they are bought in pairs
cost = items / 2 * storePrice;