#include
#include
int main() {
int i;
int sum = 0;
for(i=1;i<=50;i++) {
sum += (-2) * i * (pow(-1, i));
}
printf("%d\n", sum);
return 0;
}
您好,程序如下
#include
int main()
{
int sign=1,i,sum=0;
for(i=2;i<=100;i+=2)
{
sum+=sign*i;
sign=-sign;
}
printf("%d\n",sum);
}
采纳哦~