Array in C++

[alex k]

programe to randomly generate store and display the age of N studnets (e.g ,18,24,38 etc).the minimum age is 18 and maximum age is 75.N should be equal to 9.
1.How we can intialise all the elements of the array to -1.
2.Randomly generate and store the age of N studnets .
3.sort and display the array in ascending order .
thnks :-)

[Ancient Dragon]

1. use a loop

2. call srand( (unsigned int)time(0)); to initialize the random number generator, then for each number call rand() to get a random number.

3. google for sort algorithms. The bubble sort is the easiest to code but the slowest. In c++ you can also use the std::sort() method found in <algorithm> header file.

[alex k]

thnks Ancient Dragon :-)
i did this ..wat do u think?

srand( time(0) ); //seed random number generator
int age[3] = { 18 , 40, 65 };
int randomage = rand() % 3; //return a number from [18,75)

now if i want to calculate the avearge of students age..is that right?

Int  Sum = 0;
for( int i = 18; i < 75; i++)
{
Sum = Sum + array[i];
}

I found this context about the sort algorthim

void selectionSort ( int arr[], int size ) 
{ 
   int indexOfMin; 
   int pass; 
   int j; 

   for ( pass = 0; pass < size - 1; pass++ ) 
   { 
           indexOfMin = pass; 

           for ( j = pass + 1; j < size; j++ ) 
               if ( arr[j] < arr[pass] ) 
                   indexOfMin = j; 

           swap ( arr[pass], arr[indexOfMin] ); 
   } 
} 

// swap function for integers 
void swap ( int& x, int& y ) 
{ 
   int temp; 
   temp = x; 
   x = y; 
   y = temp; 
}

void sort()
{
    int size=57;
    int j,temp,i;
    for(i=0;i<(size-1);i++)
    {       
        for(j=i+1;j<size;j++)
        {
            if(queue[i]>queue[j])
            {
                temp=queue[i];
                queue[i]=queue[j];
                queue[j]=temp;
            }

        }
    }
    cout<<"Status: sorting done."<<endl

[Ancient Dragon]

>>int age[3] = { 18 , 40, 65 };
Why are you initializing it with some dummy data? Just initialise the array with all 0s int age[3] = {0}; >>int randomage = rand() % 3; //return a number from [18,75)

That's a number between 0 and 3, not 18 and 75

>>for( int i = 18; i < 75; i++)
The array only has 3 elements. You are trying to use the age range as the index into the array. What you want is this: for(int i = 0; i < 3; i++)