Function to invert vector c

Question

I’m a beginner in c and I’d like to know what’s going wrong with my code. I know I did a trick on the job, but that’s where I got the closest.

#include <stdio.h>

void inverte(int vetor_A[ ], int posicao)
{
    int auxiliar, tamanho_vetor = posicao - 1;

    for (posicao = 0; posicao <= tamanho_vetor; posicao++)
    {
      auxiliar = vetor_A[posicao];
      vetor_A[posicao] = vetor_A[tamanho_vetor];
      vetor_A[tamanho_vetor] = auxiliar;
      tamanho_vetor--;
      printf("%d ", vetor_A[posicao]);
    }
}

int main()
{
    int vetor_A[3], posicao;

    for (posicao = 0; posicao < 3; posicao++)
    {
        printf("Entre com os valores:\n");
        scanf(" %d", &vetor_A[posicao]);
    }

    printf("\n");

    inverte(vetor_A, posicao);

    return 0;
}

He prints it out:

Enter with the values: 3 Enter with the values: 4 Enter with the values: 5
5 4

Answer 1

Your algorithm is correct. It’s only printing half the vector, because the for within the function inverte only goes through the middle.

You can print after this loop or put in the main function after calling the inverte:

#include <stdio.h>

void inverte(int vetor_A[ ], int posicao)
{
    int auxiliar, tamanho_vetor = posicao - 1;

    for (posicao = 0; posicao <= tamanho_vetor; posicao++)
    {
      auxiliar = vetor_A[posicao];
      vetor_A[posicao] = vetor_A[tamanho_vetor];
      vetor_A[tamanho_vetor] = auxiliar;
      tamanho_vetor--;
    }
}

int main()
{
    int vetor_A[3], posicao;

    for (posicao = 0; posicao < 3; posicao++)
    {
        printf("Entre com os valores:\n");
        scanf(" %d", &vetor_A[posicao]);
    }

    printf("\n");

    inverte(vetor_A, posicao);

    int tamanho = posicao;
    for (posicao = 0; posicao < tamanho; posicao++)
    {
        printf("%d ", vetor_A[posicao]);
    }
    printf("\n");

    return 0;
}