C++ program for arranging numbers in Asceding and Descending order

#include<iostream>
using namespace std;

int main()
{
unsigned int N;
cout << "How many numbers you want to enter for arranging?(should be less than 100) ";
cin >> N;
if( N>0 && N<100 )
{
double num[100]; //array for taking numbers
int i,j; //for loops
//taking numbers
cout << "Now Enter the numbers: \n";
for( i=0 ; i<=N-1 ; i++ )
{
cin >> num[i];
}

//taking choice from user to show the output
char choice; //for choice
cout << "To arrange in ascending order press 'A' and to arrange in Descending order press 'D' and for getting both orders press 'B':\n";
cin >> choice;
double temp; //for manipulation
switch (choice)
{
case 'A': //for ascending order
{
//now manipulating for asecnding order
for( i=0 ; i<=N-1 ; i++ )
{
for ( j=i+1 ; j<=N-1 ; j++ )
{
if( num[j]<num[i] )
{
temp = num[i];
num[i] = num[j];
num[j] = temp;
}
}
}
//for printing in ascending order
cout << "The numbers in Ascending order are: \n";
for( i=0 ; i<=N-1 ; i++ )
{
cout << num[i] << endl;
}
break;
}
case 'D': //for descending order
{
//now manipulating for descending order
for(i=0 ; i<=N-1 ; i++ )
{
for( j=i+1 ; j<=N-1 ; j++ )
{
if( num[j]>num[i] )
{
temp = num[i];
num[i] = num[j];
num[j] = temp;
}
}
}
//for printing in descending order
cout << "The numbers in Descending order are: \n";
for( i=0 ; i<=N-1 ; i++ )
{
cout << num[i] << endl;
}
break;
}
case 'B': //for both orders
{
//now manipulating for asecnding order
for( i=0 ; i<=N-1 ; i++ )
{
for ( j=i+1 ; j<=N-1 ; j++ )
{
if( num[j]<num[i] )
{
temp = num[i];
num[i] = num[j];
num[j] = temp;
}
}
}
//for printing in ascending order
cout << "The numbers in Ascending order are: \n";
for( i=0 ; i<=N-1 ; i++ )
{
cout << num[i] << endl;
}

//now manipulating for descending order
for(i=0 ; i<=N-1 ; i++ )
{
for( j=i+1 ; j<=N-1 ; j++ )
{
if( num[j]>num[i] )
{
temp = num[i];
num[i] = num[j];
num[j] = temp;
}
}
}
//for printing in descending order
cout << "The numbers in Descending order are: \n";
for( i=0 ; i<=N-1 ; i++ )
{
cout << num[i] << endl;
}
break;
}

default:
cout << "Wrong Input!" <<endl;
}
}
else
cout << "The program cannot arrange the required numbers!"
<< endl;

return 0;
}