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// Sum of prime numbers 0 to 100 is : 1637
#include <stdio.h>
int sumOfprime(int num);
int main() {
int number, result;
printf("Enter a number: ");
scanf("%d", &number);
result = sumOfprime(number);
printf("Sum of prime numbers 0 to %d is : %d\n", number, result);
return 0;
}
int sumOfprime(int num) {
if (num > 1) {
if ((num % 2 == 0 && num != 2 ) || (num != 3 && num % 3 == 0)) {
return sumOfprime(num - 1);
} else {
return num + sumOfprime(num - 1);
}
} else {
// (-1) because prime numbers starts from 2.
return num - 1;
}
}