#include <stdio.h>
#include <math.h>
int main() {
int a,b,c;
a=101;
c=0;
while(a<=200){
for(b=2;b<sqrt(a);b++){
if(a%b==0)
break;
}
if(b>sqrt(a)){
printf("%5d",a);
c++;
if(c%5==0)
printf("\n");
}
a=a+1;
}
printf("\n");
printf("101~200之间共有%d个素数",c);
return 0;
}
![](https://img2018.cnblogs.com/blog/1635507/201904/1635507-20190415222613151-1863533352.png)
#include <stdio.h>
int main()
{
double a,b,c;
scanf("%lf %lf %lf", &a, &b, &c);
if(a+b>c && a+c>b && b+c>a)
{
if(a==b && a==c)
printf("构成等边三角形\n");
else if(a==b || a==c || b==c)
printf("构成等腰三角形\n");
else
printf("构成一般三角形\n");
}
else
printf("不能构成三角形\n");
return 0;
}
![](https://img2018.cnblogs.com/blog/1635507/201904/1635507-20190415220000816-2099480574.png)
![](https://img2018.cnblogs.com/blog/1635507/201904/1635507-20190415220121221-2035056260.png)
![](https://img2018.cnblogs.com/blog/1635507/201904/1635507-20190415220214430-2032104435.png)
![](https://img2018.cnblogs.com/blog/1635507/201904/1635507-20190415220311777-1613937895.png)
#include<stdio.h>
int main(){
int i,j,k;
char space=' ';
for(i=1;i<=4;i++)
{
for(j=3;j>=i;j--)
{
printf("%c",space);
}
for(k=1;k<=(2*i-1);k=k+1)
{
printf("*");
}
printf("\n");
}
return 0;
}
![](https://img2018.cnblogs.com/blog/1635507/201904/1635507-20190415220838856-1101680761.png)