Vector with pointers ordered in ascending order in C

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I’m having difficulty sorting in ascending order the values present in a vector using pointers, I tested and the problem is that it just shows the vector with the inverse typed sequence, and not in ascending order, follows the code for analysis:

int main(void){

    int vec[5] = {},aux; // Vetor e aux pra ordernar
    int *p; // ponteiro para o vetor

    for(int i=0;i<5;i++){ // obter o vetor do usuario
        printf("Digite o elemento de numero %d do vetor: ", i+1);
        scanf_s("%d",&vec[i]);
    }
    p = &vec[0]; // Ponteiro no primeiro elemento do vetor

            for (int i=0;i<5;i++) // loop de scaneamento do vetor
            {
                for (int j=0;j<5;j++)
                {
                    if ((p+i)>(p+j)) // Ordena o vetor atravez dos ponteiros
                    {
                        aux = *(p+i);
                        *(p+i) = *(p+j);
                        *(p+j) = aux;
                    }
                }
            }
    printf("\n\nSeu vetor ordenado: ["); // print do vetor ordenado
    for(int i=0;i<5;i++){
        printf(" %d ",vec[i]);
    }
    printf("]");
    return 0;


}

Could someone help me to get it in ascending order, using the pointers to navigate the vector? Thank you.

c

  • Should you not compare the content of the addresses and not the addresses themselves?

  • I’m starting now with pointers,so I’m not familiar with this,could you explain me a little? where should I compare and how

  • Here if ((p+i)>(p+j)) you are comparing two addresses and not two integers.

  • I’m comparing two pointers, which are the requests by the statement in question ''pointers to navigate the vector',the problem would be,they are then receiving the values but will not make the shape increasing,?

  • But do you want to sort the addresses or values contained in these addresses? It doesn’t make much sense to sort the pointers since it doesn’t matter the value of these pointers but the values they point to.

  • I have to sort the values inserted in the vectors,

  • Write a program that reads 5 integers and store them in one vector. From there, , using pointers to navigate the vector, the values stored in the vector must , ordered from the smallest to the largest. The ordered vector must be displayed on the screen.

  • Exchange your code snippet for: for (int i=0;i<4;i++) { for (int j=i+1;j<5;j++) { if (*(p+i) > *(p+j)) { aux = *(p+i); *(p+i) = *(p+j); *(p+j) = aux; } } }

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2 answers

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Create a function to do this sort, so you’ll be working with pointers automatically:

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


void ordenar(int *vetor, size_t tamanho);


int main(int argc, char *argv[]) {
    int vetor[5] = {5, 2, 3, 1, 4};

    ordenar(vetor, 5);
    return EXIT_SUCCESS;
}


void ordenar(int *vetor, size_t tamanho) {
    for (int i = 0; i < tamanho - 1; ++i) {
        for (int j = i + 1; j < tamanho; ++j) {
            if (vetor[i] > vetor[j]) {
                int temp = vetor[i];
                vetor[i] = vetor[j];
                vetor[j] = temp;
            }
        }
    }
}

  • Failed to create function to print vector elements, but the code has been tested and is working.

  • Thank you very much, I will do here, thanks very much, I was suffering kk

0

A simpler example using the function qsort of the standard library:

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

int compara(const void* a, const void* b)
{
    return *(int*)a - *(int*)b;
}

int main(int argc, char *argv[]) 
{
    int vetor[5] = {5, 2, 3, 1, 4};

    qsort(vetor, 5, sizeof(int), compara);

    for(int i = 0; i < 5; i++)
        printf("%d ", vetor[i]);

    return 0;
}

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