Question

I want to generate the random numbers using this loop. When i runs the apps at everytime, i want to generate the random numbers without duplicates.

Eg:

for(int i = 0; i < 5; i++)
{ 
     //  int d = random() % i;

       NSLog(@"The Value %d",i);

       NSLog(@"The random Number %d",i);
}

Actual Number Random Number
      1            4
      2            5
      3            2 
      4            1 
      5            3

Answer 1

It’s Random Permutation Generation problem. Read this: http://www.techuser.net/randpermgen.html

The main idea is (in pseudo code):

for (i=1 to n) ar[i] = i;
for (i=1 to n) swap(ar[i], ar[Random(i,n)]);

In your case:

 int ar[5],i,d,tmp;
    for(i = 0; i < 5; i++) ar[i] = i+1; 
    for(i = 0; i < 5; i++) {
        d = i + (random()%(5-i));
        tmp = ar[i];
        ar[i] = ar[d];
        ar[d] = tmp;
        NSLog(@"%d",ar[i]); 
    }