การเขียนโปรแกรมคำนวณเกรด

#include<stdio.h>
int x;
main()
{
      printf("See your grade by Sukolpat Siripattaragoon M5-9 No.7\n");
      printf("Please enter your score(0..100):");
      scanf("%d",&x);
      if(x>=0&&x<=100)
{
      if(x>=80)
        printf("Your grade is A");
      else if(x>=70)
        printf("Your grade is B");
      else if(x>=60)
        printf("Your grade is C");
      else if(x>=50)
        printf("Your grade is D");
      else
        printf("Your grade is 0(F)");
        }
        else
        printf("@$!#%error#@%#%");
getch();
}