foo.cc: In function 'int main()':
foo.cc:10:9: error: lvalue required as left operand of assignment
  if(a%3=0){
         ^
foo.cc:12:15: error: lvalue required as left operand of assignment
  }else if(a%5=0){
               ^
foo.cc:14:23: error: lvalue required as left operand of assignment
  }else if(a%5=0&&a%3==0){
                       ^

自豪的采用jd5进行评测(github.com/masnn/jd5)