code help,how to sort char array

[Builder_1]

How can i write a C++ program which prompts the user to enter names of five countries , stores them in a 2D array,sorts them alphabetical order and prints them on screen.
im unable to make it..plz help

#include <iostream>
using namespace std;
int main()

    cout<<"Enter tha names of five countries."<<endl;
    int i,j;

char arr[5][20];

for(int k=0;k<=4;k++)
{
    cin>>arr[k];
}

for( i=0;i<=4;i++)
{
    for( j=0;arr[i][j]!='\0';j++)
    {
        cout<<arr[i][j];
    }
    cout<<endl;
}

cout<<"The name of these countries in alphabetical order :"<<endl;

int x[5];

for(i=0;i<=4;i++)
{
    x[i]=arr[i][0]-64;
    cout<<x[i]<<endl;
}
const int size =5;
int pass=size-1;
int temp;
for(k=0;k<pass;k++)
{   
    for(j=0;j<pass;j++)
    {
        if(x[j]>x[j+1])
        {   temp=x[j];
            x[j]=x[j+1];
            x[j+1]=temp;
        }
    }

}


for( i=0;i<=size;i++)
{
    for( j=0;j<=15;j++)
    {

        arr[i][j]=x[i+64];
        cout<<arr[i][j];
    }
    cout<<endl;
}

    return 0;
}

[deceptikon]

Start by making sure that your driver is working the way you want using a standard sorting library. Here's one that uses qsort in C-style since you're into C-style strings:

#include <cstdlib>  // std::qsort is here
#include <cstring>
#include <iostream>

using namespace std;

namespace {
    const int COUNTRY_MAX = 5;
    const int COUNTRY_NAME_MAX = 255;

    int compare(const void *a, const void *b)
    {
        return strcmp((const char*)a, (const char*)b);
    }
}

int main()
{
    char countries[COUNTRY_MAX][COUNTRY_NAME_MAX] = {0};

    cout << "Enter " << COUNTRY_MAX << " countries.\n";

    for (int i = 0; i < COUNTRY_MAX; i++) {
        cout << i + 1 << ": ";
        cin.getline(countries[i], COUNTRY_MAX);
    }

    qsort(countries, COUNTRY_MAX, COUNTRY_NAME_MAX, compare);

    for (int i = 0; i < COUNTRY_MAX; i++) {
        cout << countries[i] << '\n';
    }
}

If this is sufficient, you're done! Otherwise, you might be asked to write your own sorting function, which is relatively straightforward and also a good learning exercise.

Keep in mind that C-style strings are arrays and do not support direct assignment. You'd need to use something like strcpy (still thinking in C mode) to copy the content of the arrays.

On a side note, 20 is too small for country names. IIRC the longest official country name pushes 70 characters, and unofficial names push 200. The ideal would be to use std::string and let each object size itself properly so you don't need to worry about such things. An added benefit is that std::string supports copying with the assignment operator and no special consideration is needed with your swap logic.

[Builder_1]

thanks

[Builder_1]

its not running properly....its truncating the string plus not working for few coutries names

[deceptikon]

Post your code and the examples that aren't working the way you think they should.

[Builder_1]

FOR country name Pakistan..the output console does not get the next four countries input