private bool IsPrime(int n) { if (n < 2) return false; else if (n == 2 || n == 3) return true; else { if (n % 2 == 0) return false; else { for (int i = 3; i <= (int)Math.Sqrt(n); i = i + 2) { if (n % i == 0) return false; } } } return true; } private void button1_Click(object sender, EventArgs e) { int sum = 0; for (int i = 1; i <= 100; i++) { if (IsPrime(i)) sum += i; } }
int sum=0; for (int num = 0; num < 100; num++) { //判断是否为质数 bool isprimenumber=true; int iii = num / 2; for (int ii = 2; ii <= iii; ii++) { if (num % ii == 0) { isprimenumber = false; break; } } sum += num; } 得到4950
55555555555,太失误了,没有加判断int sum=0; for (int num = 0; num < 100; num++) { //判断是否为质数 bool isprimenumber=true; int iii = num / 2; for (int ii = 2; ii <= iii; ii++) { if (num % ii == 0) { isprimenumber = false; break; } } if (isprimenumber) { sum += num; } }应该的1061
{
if (n < 2) return false;
else if (n == 2 || n == 3) return true;
else
{
if (n % 2 == 0) return false;
else
{
for (int i = 3; i <= (int)Math.Sqrt(n); i = i + 2)
{
if (n % i == 0) return false;
}
}
}
return true;
}
private void button1_Click(object sender, EventArgs e)
{
int sum = 0;
for (int i = 1; i <= 100; i++)
{
if (IsPrime(i))
sum += i;
}
}
int sum=0;
for (int num = 0; num < 100; num++)
{
//判断是否为质数
bool isprimenumber=true;
int iii = num / 2;
for (int ii = 2; ii <= iii; ii++)
{
if (num % ii == 0)
{
isprimenumber = false;
break;
}
}
sum += num;
}
得到4950
for (int num = 0; num < 100; num++)
{
//判断是否为质数
bool isprimenumber=true;
int iii = num / 2;
for (int ii = 2; ii <= iii; ii++)
{
if (num % ii == 0)
{
isprimenumber = false;
break;
}
}
if (isprimenumber)
{
sum += num;
}
}应该的1061