Question

C语言的题。1-3+5-7+...-99+101的值。

Answer 1

#include<stdio.h>

int main()
{
int i,flag,sum = 0;
for(i = 1,flag = 1;i <= 101;i += 2)
{
sum += i * flag;
flag *= -1;
}
printf("%d\n",sum);
return 0;
}
这是编程实现
其实这题还可以口算：sum = 101 - 2 * 50 = 1.

Answer 2

int x=1,sum = 0;
for(i=1;i<=101;i=i+2)
{
sum =sum+x*i
x=-1*x
}

Answer 3

#include <stdio.h>
void main()
{
int sum=0,flag=1;
for(int i=1;i<102;i+=2,flag*=-1)
sum+=i*flag;
printf("sum=%d",sum);

}

Answer 4

include <stdio.h>
mian()
{
int i,j,k;
k=1;
do
{
j=(k+2)*(-1);
k=k+j;
}while(j!=101);
printf("%d",k);
}

Answer 5

void main()
{
int sum=0,i=1,flag=1;

while(i<102)
(
sum+=i*flag;
i+=2;
flag*=-1;
)
printf("sum=%d\n",sum);
}