C Program to Print Prime Numbers from 1 to 100

How to write a C Program to Print Prime Numbers from 1 to 100 or Minimum to maximum and calculate the sum. Or print prime Numbers within a range using For Loop and While Loop.

C Program to Print Prime Numbers from 1 to 100 Using While Loop

In this C program to return prime numbers from 1 to 100, we used the nested while loop along with multiple if statements to get the output. If you don’t understand the While Loop, please refer to WHILE LOOP

#include <stdio.h>
 
int main()
{
  int i, a = 1, count; 
  

  while(a <= 100)
  {
    count = 0;
    i = 2;
    while(i <= a/2)
    {
      if(a%i == 0)
      {
        count++;
	break;
      }
      i++;	
    }	
    if(count == 0 && a != 1 )
    {
	printf(" %d ", a);
    }
    a++; 
  }
  return 0;
}

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It is the same as above, but we allows the user to choose the min and max value to print in between them.

#include <stdio.h>
 
int main()
{
  int i, Number, count, Minimum, Maximum; 
  
  printf("\n Please Enter the Minimum & Maximum Values\n");
  scanf("%d %d", &Minimum, &Maximum);
  Number = Minimum; 
  
  printf("Prime Numbers Between %d and %d are:\n", Minimum, Maximum);    
  while(Number <= Maximum)
  {
    count = 0;
    i = 2;
    while(i <= Number/2)
    {
      if(Number%i == 0)
      {
        count++;
	break;
      }
      i++;	
    }	
    if(count == 0 && Number != 1 )
    {
       printf(" %d ", Number);
    }
    Number++; 
  }
  return 0;
}

C Program to Print Prime Numbers from 1 to 100 Using For Loop

In this program, the first For Loop will make sure that the value is between them.

#include <stdio.h>
 
int main()
{
  int i, N, count; 
  

  for(N = 1; N <= 100; N++)
  {
    count = 0;
    for (i = 2; i <= N/2; i++)
    {
  	if(N%i == 0)
  	{
     	  count++;
  	  break;
	}
    }
    if(count == 0 && N != 1 )
    {
	printf(" %d ", N);
    }  
  }
  return 0;
}

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TIP: We already explained the logic to check whether the given is prime or not in C Program to Find Prime article in C Programming.

Instead of printing fixed values, you can allow the user to decide the minimum and maximum values. This program allows the user to enter Minimum and Maximum values — next, this C program prints prime numbers between Minimum and Maximum values using For Loop.

#include <stdio.h>
 
int main()
{
  int i, val, count, Minimum, Maximum; 

  printf("\n Please Enter the Minimum & Maximum Values\n");
  scanf("%d %d", &Minimum, &Maximum);
 
  printf("Between %d and %d are:\n", Minimum, Maximum);  
  for(val = Minimum; val <= Maximum; val++)
  {
    count = 0;
    for (i = 2; i <= val/2; i++)
    {
      if(val%i == 0)
      {
  	count++;
  	break;
      }
    }
    if(count == 0 && val != 1 )
    {
       printf(" %d ", val);
    }  
  }
  return 0;
}

 Please Enter the Minimum & Maximum Values
20
150
Between 20 and 150 are:
 23  29  31  37  41  43  47  53  59  61  67  71  73  79  83  89  97  101  103  107  109  113  127  131  137  139  149

C Program to calculate Sum of Prime Numbers from 1 to 100

This program finds prime numbers from 1 and 100, and it is going to add them to calculate the sum.

#include <stdio.h>
 
int main()
{
  int i, Num, count, Sum = 0; 
  
  for(Num = 1; Num <= 100; Num++)
  {
    count = 0;
    for (i = 2; i <= Num/2; i++)
    {
  	if(Num%i == 0)
  	{
  	   count++;
  	   break;
	}
    }
    if(count == 0 && Num != 1 )
    {
	Sum = Sum + Num;
    }  
  }
  printf(" Sum between 1 to 100 =  %d", Sum); 
  return 0;
}

 Sum between 1 to 100 =  1060

Instead of adding first 1 to 100, you can allow the user to decide the minimum and maximum values. This program allows the user to enter Minimum and Maximum values. Next, this C program finds the sum of prime numbers between Minimum and Maximum values using For Loop.

#include <stdio.h>
 
int main()
{
  int i, Num, count, Sum = 0, Minimum, Maximum; 

  printf("\n Please Enter the Minimum & Maximum Values\n");
  scanf("%d %d", &Minimum, &Maximum);
  
  for(Num = Minimum; Num <= Maximum; Num++)
  {
    count = 0;
    for (i = 2; i <= Num/2; i++)
    {
  	if(Num%i == 0)
  	{
     	  count++;
  	  break;
	}
    }
    if(count == 0 && Num != 1 )
    {
       Sum = Sum + Num;
    }  
  }
  printf(" Sum between %d and %d =  %d", Minimum, Maximum, Sum); 
  return 0;
}

 Please Enter the Minimum & Maximum Values
100
200
 Sum between 100 and 200 =  3167