Question

用JAVA编写程序。求1-3+5-7+……-99+101的值

Answer 1

public class NTest_1
{
public static void main(String [] args)
{
int l = 0;
boolean b = true;
for (int i = 1;i <= 101;i += 2)
{
if (b)
{
l += i;
b = false;
}
else
{
l -= i;
b = true;
}
}
System.out.println(l);
}
}

Answer 2

int result=1;
int n=1;
for(int i=1;i<=99;i=i+2)
{
if(n%2==1)
{result+=i+2;n++}
else
{result-=i+2;n++}
}
System.out.println(result);

Answer 3

草,这么简单的问题都问