55 lines
958 B
C
55 lines
958 B
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#define YES 1
|
|
#define NO 0
|
|
|
|
int t[300000];
|
|
int tlen=0;
|
|
|
|
char is_prime(int n) {
|
|
int i;
|
|
for (i=0; i<tlen ; i++) {
|
|
if ( n % t[i] == 0 )
|
|
return NO;
|
|
}
|
|
return YES;
|
|
}
|
|
|
|
void gen_prime_up_to(int n) {
|
|
int i=2;
|
|
while (i<n) {
|
|
if ( i % 20000 == 0) {
|
|
printf("%d pc\n", i*100/n);
|
|
}
|
|
if (is_prime(i)) {
|
|
t[tlen]=i;
|
|
tlen++;
|
|
}
|
|
i++;
|
|
}
|
|
}
|
|
|
|
double sum_up_to(int n) {
|
|
int i;
|
|
double sum=0;
|
|
gen_prime_up_to(n);
|
|
printf("tlen = %d\n", tlen);
|
|
for (i=0; i<tlen; i++) {
|
|
printf("%d\n", t[i]);
|
|
sum+=t[i];
|
|
}
|
|
return sum;
|
|
}
|
|
|
|
int main(int argc, char *argv[]) {
|
|
int val=2000000;
|
|
int i;
|
|
// double sum;
|
|
printf("Sum up to %d is %lf\n",val, sum_up_to(val));
|
|
// for (i=0; i<2000000 ; i++) {
|
|
// sum+=i;
|
|
// }
|
|
// printf("Sum up to %d is %lf\n",val, sum);
|
|
}
|