用筛选法求n以内的素数

#include<stdio.h>#include<math.h>void prime(int arr[],int in); int main(){int in;scanf("%d",&in);int arr[in+1];for(int i=0;i<in;i++){arr[i]=i;arr[1]=0;}prime(arr,in);int count=0;for(int i=2;i<in;i++){if(arr[i]!=0){printf("%d",arr[i]);count++;if(count%10==0){printf("\n");}else printf("\t");}}return 0;}//筛选法求素数void prime(int arr[],int n){for(int i=2;i<sqrt(n);i++){for(int j=i+1;j<=n;j++){if(arr[i]!=0&&arr[j]!=0)if(arr[j]%arr[i]==0)arr[j]=0;}}return;}