Lab4 (C compiled in C++)

#include <stdio.h>

int main(void)
{
    float max = 0;
    float score = 0;
    float percentage = -1;
    char quit = 'a';
    char letter = 'F';
    float remainder = 0;

    do{
        printf("Max score of your exam: ");
        scanf("%f", &max);
    }while(max == 0);


    //Potential for a do while loop or a while loop until a valid score is entered
    printf("What is your score: ");
    scanf("%f", &score);

    percentage = score/max * 100;

    if(score > max) {
        printf("Error, score is invalid. Please reset the board\n");
        goto end;
    }
    else if(percentage >= 90) {
        letter = 'A';
    }
    else if(percentage >= 80) {
        letter = 'B';
    }
    else if(percentage >= 70) {
        letter = 'C';
    }
    else if(percentage >= 60) {
        letter = 'D';
        }
    else{
        letter = 'F';
    }

    //Next Letter Grade
    if(percentage < 90) {
        remainder = 10 - ( (int) percentage % 10);

        printf("You got a %c, and you were %0.2f%% away from the next letter grade.\n", letter, remainder);
    }else{
        printf("You got a %c, you can not move up a letter grade!\n", letter);
    }


    end: printf("Program finished, press any key to quit ... ");
    getchar();
    getchar();
    scanf("%c", &quit);
    printf("\nYou pressed %c to quit the program\n", quit);

    printf("Goodbye\n");

    return 0;
}