Mã chấm: 268475

Main.cc: In function ‘double pi(int)’:
Main.cc:7:6: warning: pointer to a function used in arithmetic [-Wpointer-arith]
   pi += (i%2==0?1:-1)/(2*i+1);
   ~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cc:7:29: error: assignment of read-only location ‘pi’
   pi += (i%2==0?1:-1)/(2*i+1);
                             ^
Main.cc:7:29: error: cannot convert ‘double (*)(int)’ to ‘double(int)’ in assignment
Main.cc: In function ‘int main()’:
Main.cc:15:8: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%ld", &n);
   ~~~~~^~~~~~~~~~~