请问，我的这程序怎么报错了？

#include<stdio.h>
#include<math.h>
int main()
{
    int i,p,n;
    i=1;
    p=1/n;
    n=2;
    do
    {
        while(n%2=0)              //left operation must be l-value
        {
            p=-p;
        }
        i=i+p;
        n=n+1;
    }
    while(n>100);
    printf("total=%d\n",i);
    return 0;
}