Task: Read a percentage and assign a grade via an if–else ladder (A, B, C, D, F). Validate input lies in 0–100.
/*
Program: Grade Calculator from Percentage (U2)
What it does:
- Reads a percentage in the range 0..100 (float allowed).
- Assigns grade using an if–else ladder: e.g., >=90 A, >=80 B, >=70 C, >=60 D, else F.
*/
#include <stdio.h>
int main(void) {
double perc;
printf("Enter percentage (0..100): ");
if (scanf("%lf", &perc) != 1) {
printf("Invalid input. Please enter a number.
");
return 0;
}
if (perc < 0.0 || perc > 100.0) {
printf("Percentage must be between 0 and 100.
");
return 0;
}
/* If–else ladder for grade */
if (perc >= 90.0) printf("Grade: A
");
else if (perc >= 80.0) printf("Grade: B
");
else if (perc >= 70.0) printf("Grade: C
");
else if (perc >= 60.0) printf("Grade: D
");
else printf("Grade: F
");
return 0;
}