Answer to Question #50599 in C++ for Umer

Question

Start with an array of pointers to strings representing the days of the week, as found in the PTRTOSTR program in this chapter. Provide functions to sort the strings into alphabetical order, using variations of the bsort() and order() functions from the PTRSORT program in this chapter. Sort the pointers to the strings, not the actual strings.

Answer 1

// main.cpp -- function for sorting array of pointers to strings
#include <iostream>
#include <cstring> // strcmp()
#include <algorithm> // swap()
// Sorts array of C strings of given size into alphabetical order
void sort_strings(char *strings[], int size);
// Prints array of C strings
void print_array(char *strings[], int size);
int main()
{
const int DAYS_IN_WEEK = 7;
char *days_of_week[DAYS_IN_WEEK] = {
"Sunday",
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday",
"Saturday"
};
std::cout << "Original array: " << std::endl;
print_array(days_of_week, DAYS_IN_WEEK);
std::cout << "Sorted array: " << std::endl;
sort_strings(days_of_week, DAYS_IN_WEEK);
print_array(days_of_week, DAYS_IN_WEEK);
return 0;
}
void sort_strings(char *strings[], int size)
{
// Bubble sort
for (int i = 0; i < size - 1; ++i)
{
for (int j = i + 1; j < size; ++j)
{
if (std::strcmp(strings[i], strings[j]) > 0)
{
std::swap(strings[i], strings[j]);
}
}
}
}
void print_array(char *strings[], int size)
{
for (int i = 0; i < size; ++i)
std::cout << strings[i] << " ";
std::cout << std::endl;
}