if else

#include <stdio.h>
int main()
{
  int num1,num2;
  char op;
  float ans;
  scanf("%d %c %d", &num1 ,&op ,&num2);
  if(op == '+')
  {
  ans = num1 + num2;
  }
  else if(op == '-')
  {
  ans = num1 - num2;
  }
  else if(op == '*')
  {
  ans = num1 * num2;
  }
  else if(op == '/')
  {
  ans = (float)num1 / num2;
  }
  printf("ans: %f\n",ans);
return 0;
}

---------------------------------------------------------------------------------------------------------------------

#include <stdio.h>
int main()
{
int score;
char grade;
scanf("%d",&score);
if(score>=90 && score<=100)
{
printf("grade = A\n");
}
else if(score>=80 && score<90)
{
printf("grade = B\n");
}
else if(score>=70 && score<80)
{
printf("grade = C\n");
}
else if(score>=60 && score<70)
{
printf("grade = D\n");
}
else
{
printf("grade = E\n");
}
}