Organizing names by last name with three of the same surnames (C++)? - c++

Question

I have an assignment to sort a list of names alphabetically by last name. However, there are three names with the same surname and I can't get the first names to alphabetize with the surnames. Have to code own bubble sort or other sorting algorithm. I chose bubblesort because it's one of the only ones we've learned so far. Any help is appreciated. Everything works except the correct assortment.
Here is my code:
// my name
// Program 6
// This program will show a list of names in a variety of orders.
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
const int size = 25;
void showContacts_FNLN(string fnameArray[], string lnameArray[], int size);
void showContacts_LNFN(string lnameArray[], string fnameArray[], int size);
void reverseContacts_FNLN(string fnameArray[], string lnameArray[], int size);
void reverseContacts_LNFN(string fnameArray[], string lnameArray[], int size);
void searchLasname(string lnameArray[], string fnameArray[], int size);
void searchFirname(string fnameArray[], string lnameArray[], int size);
void bubbleSort(string lnameArray[], string fnameArray[], int size);
int main(int argc, const char * argv[])
{
int count = 0;
int ans;
ifstream nameData;
string lnameArray[size];
string fnameArray[size];
string lname, fname;
nameData.open("names.txt");
while(nameData >> fname >> lname)
{
fnameArray[count] = fname;
lnameArray[count] = lname;
count ++;
}
bubbleSort(lnameArray, fnameArray, size);
while(ans != 9)
{
cout << "What would you like to do?" << endl;
cout << "1) display contacts by first name and last name" << endl;
cout << "2) display contacts by last name and first name" << endl;
cout << "3) display contacts by first name and last name in reverse order" << endl;
cout << "4) display contacts by last name and first name in reverse order" << endl;
cout << "5) search for contact by last name" << endl;
cout << "6) search for contact by first name" << endl;
cout << "9) exit" << endl;
cout << "Enter: ";
cin >> ans;
cout << endl;
switch(ans)
{
case 1: showContacts_FNLN(fnameArray, lnameArray, size); // shows contacts in FN-LN order
break;
case 2: showContacts_LNFN(lnameArray, fnameArray, size); // LN-FN order
break;
case 3: reverseContacts_FNLN(fnameArray, lnameArray, size); // reversed FN-LN order
break;
case 4: reverseContacts_LNFN (fnameArray, lnameArray, size); // reversed LN-FN order
break;
case 5: searchLasname(lnameArray, fnameArray, size); // searches based on LN
break;
case 6: searchFirname(fnameArray, lnameArray, size); // searches based on FN
break;
case 9: cout << "Goodbye!" << endl;
break;
}
}
nameData.close();
return 0;
}
void showContacts_FNLN(string fnameArray[], string lnameArray[], int size)
{
for(int i=0; i<size; i++)
{
cout << fnameArray[i] << " " << lnameArray[i] << endl;
}
cout << endl;
}
void showContacts_LNFN(string lnameArray[], string fnameArray[], int size)
{
for(int i=0; i<size; i++)
{
cout << lnameArray[i] << ", " << fnameArray[i] << endl;
}
cout << endl;
}
void reverseContacts_FNLN(string fnameArray[], string lnameArray[], int size)
{
for(int i=(size-1); i>=0; i--)
{
cout << fnameArray[i] << " " << lnameArray[i] << endl;
}
cout << endl;
}
void reverseContacts_LNFN(string fnameArray[], string lnameArray[], int size)
{
for(int i=(size-1); i>=0; i--)
{
cout << lnameArray[i] << ", " << fnameArray[i] << endl;
}
cout << endl;
}
void searchLasname(string lnameArray[], string fnameArray[], int size)
{
int c = 0;
string slnam;
cout << "Enter a last name: ";
cin >> slnam;
for(int i=0; i<size; i++)
{
if(slnam==lnameArray[i])
{
cout << lnameArray[i] << ", " << fnameArray[i] << endl;
c++;
}
}
if (c == 0)
{
cout << "There is no match.";
cout << endl;
}
cout << endl;
}
void searchFirname(string fnameArray[], string lnameArray[], int size)
{
int c = 0;
string sfnam;
cout << "Enter a first name: ";
cin >> sfnam;
for(int i=0; i<size; i++)
{
if(sfnam==fnameArray[i])
{
cout << fnameArray[i] << " " << lnameArray[i] << endl;
c++;
}
}
if (c==0)
{
cout << "There is no match." << endl;
}
cout << endl;
}
void bubbleSort(string lnameArray[], string fnameArray[], int size)
{
string tmp, tmp2;
//int count=0;
for( int i = 1; i <= size - 1; i++ )
{
for( int j = 0; j < size - i; j++ )
{
//count++;
if( lnameArray[j] > lnameArray[j+1] )
{
tmp = lnameArray[j];
lnameArray[j] = lnameArray[j+1];
lnameArray[j+1] = tmp;
}
if(lnameArray[j] == lnameArray[j+1])
{
if(fnameArray[j] > fnameArray[j+1])
{
tmp = lnameArray[j];
lnameArray[j] = lnameArray[j+1];
lnameArray[j+1] = tmp;
tmp2 = fnameArray[j];
fnameArray[j] = fnameArray[j+1];
fnameArray[j+1] = tmp2;
}
}
}
}
//cout << "count = " << count << endl;
}

Answer 1

Here you go:
void bubbleSort(string lnameArray[], string fnameArray[], int size)
{
for( int i = 0; i < size - 1; i++ )
{
for( int j = 0; j < size - i - 1; j++ )
{
string name1 = lnameArray[j] + fnameArray[j];
string name2 = lnameArray[j + 1] + fnameArray[j + 1];
if(name1.compare(name2) > 0)
{
string tmp = lnameArray[j];
lnameArray[j] = lnameArray[j + 1];
lnameArray[j + 1] = tmp;
tmp = fnameArray[j];
fnameArray[j] = fnameArray[j + 1];
fnameArray[j + 1] = tmp;
}
}
}
}
Instead of having another 'if' for those that have similar last names, I combined the last name and the first name instead then used it for comparison.
I also noticed in your code in for( int j = 0; j < size - i; j++ ) that you forgot to add - 1 after size - i. Once j == size - i - 1 (assuming that i == 0 currently) then you use j + 1 to access an index, this will cause a segmentation fault since you're accessing an index beyond its range.

Answer 2

Your sort doesn't work because you change the position of the last names only (except for the case where two last names are equal.)
You should use a struct to store this information together in one array. Then you can simplify your code a lot:
struct Person {
Person() = default;
Person(string firstname, string lastname) : firstname(std::move(firstname)), lastname(std::move(lastname)) {}
string firstname;
string lastname;
};
void showContacts_FNLN(Person personArray[], int size) {
for (int i = 0; i < size; i++) {
cout << personArray[i].firstname << " " << personArray[i].lastname << endl;
}
cout << endl;
}
void bubbleSort(Person personArray[], int size) {
for (int i = 1; i <= size - 1; i++) {
// The condition must size - i - 1 because otherwise personArray[j+1] is faulty
for (int j = 0; j < size - i - 1; j++) {
if (personArray[j].lastname > personArray[j+1].lastname
|| (personArray[j].lastname == personArray[j+1].lastname &&
personArray[j].firstname > personArray[j+1].firstname)) {
auto tmp = std::move(personArray[j]);
personArray[j] = std::move(personArray[j+1]);
personArray[j+1] = std::move(tmp);
}
}
}
}
int main(int argc, const char * argv[]) {
int count = 0;
ifstream nameData;
Person personArray[size];
string lname, fname;
nameData.open("names.txt");
while(nameData >> fname >> lname) {
personArray[count] = Person(fname, lname);
count++;
}
nameData.close();
bubbleSort(personArray, size);
showContacts_FNLN(personArray, size);
return 0;
}
I removed some non-essential parts from this example to keep it very short but you should get the idea. (Note that my code makes use of C++11 move semantics, if this confuses you, just remove them.)
Some more suggestions:
Do not use using namespace std;. (The internet will tell you why.)
If you can, use std::array, which eliminates the need to always pass the size of the arrays and allows you to use a C++11 range for loop.