#include <stdio.h>
void func(int n){
int count = 0;
for(int i = 2; i <= n; i++){
if(prime(i) == 1){
count++;
}
}
printf("%dは%d番目の素数\n", n
, count
); }
int prime(int n){
int i;
int sosuu = 1;
for(i=2; i<n; i++){
if(n%i == 0){
sosuu=0;
break;
}
}
return sosuu;
}
int main(void) {
int i;
int x;
for(int i=2; i<20; i++){
x = prime(i);
if (x == 1){
func(i);
}
}
return 0;
}
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