用C语言编写一个程序，将100以内不是素数的数字求和并输出．

Question

如题所述

Answer 1

# include <stdio.h>
int isPrime(int l)
{
int i;
for(i=2;i*i<=l;i++)
{
if(l%i==0)
{
return 0; //is not a prime
}
}
return 1; // is a prime
}

void main()
{
int count=0;
int i;
int sum=0;
for(i=2;i<=100;i++)
{
if(!isPrime(i))
{
printf("%d ",i);
count++;
sum+=i;
}
}
printf("\n");
printf("count is %d\n",count);
printf("sum is %d\n",sum);
}

包含求和以及不时素数的总个数

Answer 2

#include <stdio.h>
int main(void)
{
int a[100],i,j;
int sn=2;
for (i = 0; i<100; i++) a[i]=i+1;
for (i = 1; i<100; i++) {
if (!a[i]) continue;
for (j=i+1; j<100; j++) {
if (a[j]&&a[j]%a[i]==0) {
sn+=a[j];
a[j]=0;
}
}
}
printf("%d\n",sn);
return 0;
}