nth prime number
Suggest an efficient algorithm to find nth prime number,where n is run time option.
Given an integer n, write a function that returns count of trailing zeroes in n!. Examples: Input: n = 5 Output: 1 Factorial of 5 is 20 which has one trailing 0. Input: n = 20 Output: 4 Factorial of 20 is 2432902008176640000 which has 4 trailing zeroes. Input: n = 100 Output: 24
int *arr;
ReplyDeleteint getNextPrime(int index)
{
int i;
int check=0;
bool flag = false;
for(i=arr[index-1]+2;;i=i+2)
{
flag = false;
check =0;
while(check < index && arr[check]<=sqrt(i))
{
if(i%arr[check] == 0)
{
flag = true;
break;
}
check++;
}
if(!flag)
{
return i;
}
}
}
int main()
{
int n,i=2;
int k=3;
cout<<"Enter the value of n"<>n;
arr = (int*)malloc(sizeof(int)*n);
arr[0]=2;arr[1] = 3;
while(i<n)
{
arr[i] = getNextPrime(i);
i++;
}
cout<<arr[n]<<"\n";
return 0;
}