2984: Find prime numbers within n (1-1)

Time Limit: 0 Sec   Memory Limit: 128 MB
Commits: 239   Resolved: 35
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Topic description

Input an integer n, find the prime numbers within n, every ten lines, take the best possible algorithm.

enter

n

output

prime numbers up to n

sample input

100

Sample output

    2    3    5    7   11   13   17   19   23   29
   31   37   41   43   47   53   59   61   67   71
   73   79   83   89   97

hint

source

Hou Wenhan

Code:

#include<stdio.h>
int main()
{
int i,t;
int n,x=0;
int f(int a);
scanf("%d",&n);
for(i=2;i<=n;i++)
{
if(f(i))
x++,printf("%5d",i);
if(x%10==0)
printf("\n");
}
return 0;
}
int f(int a)
{
int i;
for(i=2;i<a;i++)
if(a%i==0)
return 0;
return 1;
}