C Array Of Pointers
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C Exercise Example17
C Recursion
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C Examples Check Armstrong Number
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C Examples Octal Decimal Convert
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C Examples Binary Decimal Convert
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C If
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C Examples Add Matrix
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C Examples Five Fish Html
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C Function Strcpy
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C Examples Structure Store Information
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C Exercise Example90
C Examples Access Array Pointer
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C Examples Sum Prime Numbers
C Exercise Example64
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C Examples Vowel Consonant Frequency String
C Exercise Example91
C Multi Dimensional Arrays
C Examples Add Numbers
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C Examples Ascii Value Character
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C Pointer To Pointer
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C Standard Library Errno H
C Strings
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C Function Memmove
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C Enum
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C Bit Fields
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C Language Example - Check if a Number is the Sum of Two Primes
Calculate if a number is the sum of two prime numbers.
Example
#include <stdio.h>
int checkPrime(int n);
int main()
{
int n, i, flag = 0;
printf("Enter a positive integer: ");
scanf("%d", &n);
for(i = 2; i <= n/2; ++i)
{
// Check condition
if (checkPrime(i) == 1)
{
if (checkPrime(n-i) == 1)
{
printf("%d = %d + %d\n", n, i, n - i);
flag = 1;
}
}
}
if (flag == 0)
printf("%d cannot be expressed as the sum of two primes.", n);
return 0;
}
// Function to check prime number
int checkPrime(int n)
{
int i, isPrime = 1;
for(i = 2; i <= n/2; ++i)
{
if(n % i == 0)
{
isPrime = 0;
break;
}
}
return isPrime;
}
Output result:
Enter a positive integer: 34
34 = 3 + 31
34 = 5 + 29
34 = 11 + 23
34 = 17 + 17