Question

试用C语言编程实现以下功能：求出表达式1-2+3-4+5-...-100的结果。

Answer 1

#include<stdio.h>
void main()
{
int i,s=0;
for(i=1;i<=100;i++)
{
if(i%2==0)
s-=i;
else
s+=i;
}
printf("1-2+3-4+5-...-100=%d\n",s);
}

Answer 2

#include <stdio.h>

void main()
{
int t = -1, k = 0, sum = 0;
while(++k <= 100)
{
t *= -1;
sum += t*k;
}
printf("sum = %d\n", sum);
}

Answer 3

基数偶数和之差