Question

计算公式s=1-12+ 123-1234+ 12345c语言编程

Answer 1

#include<stdlib.h>
#include<stdio.h>
int main()
{
int sum=0,i=1,temp=0;
while(i<6)
{

temp=temp*10+i;
if(i % 2 != 0)
sum+=temp;
else
sum -= temp;
i++;
}
printf("1-12+123-1234+12345=%d\n",sum);
}

Answer 2

#include<stdlib.h>
#include<stdio.h>
int main()
{
int s=0;
int temp1=0;
int temp2=0;
int i=0;
for (i=1;i<=5;i++)
{
temp2=temp1*10+1;
temp1=i;
s+=temp2;
}
printf("%d",s);
return 0;
}

Answer 3

int s;
s=1-12+123-1234+12345;