Mã chấm: 268255

Main.cc: In function ‘int main()’:
Main.cc:17:10: warning: left operand of comma operator has no effect [-Wunused-value]
     if (0<=A,B<=100 && 1<=X,Y<=100)
         ~^~~
Main.cc:17:21: warning: right operand of comma operator has no effect [-Wunused-value]
     if (0<=A,B<=100 && 1<=X,Y<=100)
              ~~~~~~~^~~~~~~
Main.cc:19:15: warning: unused variable ‘tongtien’ [-Wunused-variable]
         float tongtien = A * X + B * Y;
               ^~~~~~~~
Main.cc:21:71: error: ‘tongtien’ was not declared in this scope
     printf("tong so tien can mang theo de mua het tat ca la: %.2f\n", tongtien);
                                                                       ^~~~~~~~
Main.cc:10:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &A);
     ~~~~~^~~~~~~~~~
Main.cc:12:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &B);
     ~~~~~^~~~~~~~~~
Main.cc:14:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%f", &X);
     ~~~~~^~~~~~~~~~
Main.cc:16:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%f", &Y);
     ~~~~~^~~~~~~~~~