Close loop when typing specific character

Question

Hello! I need to resolve the following question, but I’m not getting it.

Write an algorithm that calculates the average arithmetic of the students' 3 grades (number undetermined of pupils) of a class. The algorithm should read, in addition to the notes, the code of the student and should be terminated when the code is zero

I wrote the code below, I do not know what is wrong, because when "code = 0" it does not close. Someone can help me?

main()
{

int codigo, n1, n2, n3, i;
float media;


while(codigo != 0){
    for(i= 0; i >= 0; i++){
            printf("Digite o código do aluno:\n");
            scanf("%d", &codigo);
            printf("Digite as 3 notas do aluno:\n");
            scanf("%d %d %d", &n1, &n2, &n3);
            media = ((n1+n2+n3)/3);
            printf("Media = %.2f\n", media);
    }
}
return 0;
}

Answer 1

The line with the for this wrong.

Note that it is written for(i= 0; i >= 0; i++), which means:

for i of 0, while i > = 0, incrementing i in one unit per cycle, run...

That is, as your variable i is initialized with 0, and she’s always augmented, she’ll never be less than 0, so this for will never be finalized.

In fact, there is, if you like, no reason for it (at least according to the specification of the exercise cited), so it can be removed.

main() {
    int codigo, n1, n2, n3;
    float media;

    while(codigo != 0){
        printf("Digite o código do aluno:\n");
        scanf("%d", &codigo);
        printf("Digite as 3 notas do aluno:\n");
        scanf("%d %d %d", &n1, &n2, &n3);
        media = ((n1+n2+n3)/3);
        printf("Media = %.2f\n", media);
    }
    return 0;
}

Another factor that should be observed is that when typing 0 for the student code, we do not want the grades to be read (since we are not associating them with a student). We then read the notes only if the code is different from 0 (codigo != 0).

main() {
    int codigo, n1, n2, n3;
    float media;

    while(codigo != 0){
        printf("Digite o código do aluno:\n");
        scanf("%d", &codigo);
        if ( codigo != 0 ) {
            printf("Digite as 3 notas do aluno:\n");
            scanf("%d %d %d", &n1, &n2, &n3);
            media = ((n1+n2+n3)/3);
            printf("Media = %.2f\n", media);
        }
    }
    return 0;
}

I hope I’ve helped.