Need help for this 3 programs in C.

1.
Write a program that will print all prime numbers from a given range which consist of only odd digits. At the end to print the number of primes which satisfy the condition.

i can use only stdio.h not conio or anything else.

2.
Write a program for each of the numbers are printed after the number of transformations that the original number becomes single digits, and print thereceived transformed number. With each transformation of the original number, it is replaced by the sum of its digits.

Example: 721->10->1

3.
To write a program that print diamond asterisks (*). Diamond should have 2 * N - 1 queues, where N is read from the keyboard.
Example: For N = 3 print

--*
-***
*****
-***
--*

What have you tried?

i only know the algorithm for the first one
int i,j,r1,r2,c=0
for i=r1;i<=r2;i++
for j=2;j<=i/2;j++

i am beginner in this so i don't know much.
for the second and third programs i have no die how to start.
So if you or anyone else can write them i will be very thakfull

Stop trying to write programs, and start trying to write out into words what you need to do for each one. Turn your words into a list of things to do. If you can't recreate the output from reading your list, then you have done it wrong. Then turn that into pseudo-code.


Quzah.

Quote:

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Originally Posted by laserlight

What have you tried?

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Couldn't the admins implement a function to add the above quote and the OPs answer to it beneath the first posting of a homework thread automatically? The first three postings are always the same anyway...