Repeat user and password typing attempts

Question

I wanted a program that checks the user and password, if it was correct to display a message, otherwise I would repeat the check and if the attempts were equal to 3, it would display the limit message of reached attempts.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    char user[20];
    int senha, contador = 0;

    printf("Entre com o usuario: ");
    gets(user);

    printf("Entre com a senha: ");
    scanf("%d", &senha);

    while((strcmp(user, "leonardo") == 0) && senha == 123) {
    if(1) {

        printf("\nAcesso concedido.\n");
        break;

     } else {
       contador = contador + 1;
       gets(user);
       scanf("%d", &senha);

       } if(contador == 3) {
       printf("Limite de tentativas alcancadas.\n");
       }
    }

    printf("Fim.\n");
    return 0;
}

I’m having trouble with the loops.

Answer 1

There is a lot of code repetition in it. Then it gets confused and starts to have some logic problems. It would be better to do every check inside the loop.

Note that the counting of trials should occur always and not conditionally. It is much simpler to understand the flow when the values of the variables reflect what they actually represent. If an attempt was made, the variable must be 1. If you made one more attempt, you must add it. And check if you have reached the number of attempts allowed.

Obviously it would be interesting to do something beyond this, but it is an initial basis that works:

char user[20];
int senha, contador = 0;
do {
    printf("Entre com o usuario: ");
    gets(user);
    printf("Entre com a senha: ");
    scanf("%d", &senha);
    // aqui as credenciais estão corretas
    if (!strcmp(user, "leonardo") && senha == 123) {
        printf("\nAcesso concedido.\n");
        break;
    }
    contador++;
} while (contador < 3);
if (contador == 3) printf("Limite de tentativas alcancadas.\n");
printf("Fim.\n");

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

Test exceeding the limit.

I made a change because it is not recommended to use the gets() and some compilers cannot use it in its default form (I cannot configure it in ideone).