c 求素数

[wnhh]

int i, k, m;
int leap = 0;
int counter = 0;

for(i = 2; i <= 100; i++)
{ leap = 0;
m = sqrt((float)i);
for(k = 2; k <= m; k++)
if(i % k == 0)
leap = 1;
if(leap == 0)
{
counter += 1;
//printf(" '%d ", counter);
printf("%d ", i);
}
if(counter % 5 == 0)
printf("\n");

}//求100以内的素数，每5个元素换一行。但换行 不正确，中间有大块空白？怎么回事

[测试NULL]

找到原因了，请看注释
建议楼主给每个循环语句，if语句都加大括号 {}，这样结构看得更清楚

#include <stdio.h>
#include <math.h>

int main()
{
    int i, k, m;
    int leap = 0;
    int counter = 0;
    
    for(i = 2; i <= 100; i++)
    {
        leap = 0;
        m = (int)sqrt((float)i);
        for(k = 2; k <= m; k++)
        {
            if(i % k == 0)
            {
                leap = 1;
            }
        }
        if(leap == 0)
        {
            counter += 1;
            printf("%d ", i);

            if(counter % 5 == 0)   /*放这里就OK了*/
            {
                printf("\n");
            }
        }
        /*
        if(counter % 5 == 0)   放外面，不是素数的情况下counter%5==0也会输出换行
        {
            printf("\n");
        }
        */
    }
    return 0;
}

[無_1024]

#include <stdlib.h>
#include <stdio.h>
#include <math.h>

int main ()
{
    int i, k, m;
	int leap = 0;
	int counter = 0;
	
	for(i = 2; i <= 100; i++)
	{ 
		leap = 0;
		m = (int)sqrt((double)i);
		for(k = 2; k <= m; k++)
		{
			if(i % k == 0)
				leap = 1;
		}
		if(leap == 0 )
		{
			counter += 1;
			//printf(" '%d ", counter);
			printf("%5d", i);
			if(counter % 5 == 0)
				printf("\n");
		}		
	}//求100以内的素数，每5个元素换一行。但换行 不正确，中间有大块空白？怎么回事
    return 0;
}

[wnhh]

哦， 原来是这样

[wzhwisk]

这个很简单，我会做