recursion array

[Gordo Miguel]

hi guys!!!
this is my first post and I am fairly new programming in C,
I wanted to ask about a problem. I have 2 array of numbers and I have to merge them with each other recursively orderly, not how to do it, thanks for a good guide, help me to think about, thanks

[dotnet13]

can you give a sample input and output so it'll be easy to understand?

[Gordo Miguel]

arrayA[4,44,54,1,65,65] arrayB[8,87,4,23,12,433] and together arrayC[1,4,4,12,23,44,54,65,65,87,433] with a loop or recursion, the name that you like

[grumpy]

Easy.

Make sure arrayC is large enough to hold both arrayA and arrayB (i.e. length is at least the sums of the lengths of arrayA and arrayB).

Copy arrayA to arrayC, starting at the beginning. Starting one past the last element in ArrayC that was copied from ArrayA, copy arrayB to arrayC.

Sort the array in ascending order. Remove any duplicate values (if that is required - your example suggests it isn't).

And, no, I'm not going to provide code. The description above is a big enough hint on what you need to do.

[dotnet13]

arrayA[4,44,54,1,65,65] arrayB[8,87,4,23,12,433] and together arrayC[1,4,4,12,23,44,54,65,65,87,433] with a loop or recursion, the name that you like

with loop it'll be like this:

 int A[5]={1,3,5,7,9}, B[]={2,4,6,8,10}, C[10];

int count=0;

for(int i=0;i<5;i++)

	{

		C[i]=A[i];

		count++;

	}

for(int i=0;i<5;i++)

	{

		C[count]=B[i];

		count++;

	}


for(int i=0;i<10;i++)

   {

	   printf("%d ",C[i]);

   } 

After merging you can do the sorting using any sorting algorithm, hopefully you'll be able to do that.

[Gordo Miguel]

thanx guys, i dont want the code, but the ideas help me a lot, now doing with a recursion it heavier

[Gordo Miguel]

well, finish the code.
I can do it with recursion?? the juntarArreglos function??

#include <stdio.h>
#define MAX 5
#define MAX2 10


void inicializo(int *a, int *);
void cargarArreglos(int *a, int *b);
void juntarArreglos(int *a, int *b);
void mostrar(int *c);


int main(){
int a[MAX];
int b[MAX];
int c[MAX2];
int i=0;

    inicializo(a,b);
    cargarArreglos(a,b);
    juntarArreglos(a,b);



return 0;
}

/*Inicializo el arreglo */
void inicializo(int *valores, int *valoresb)
{
int i;
int valorinicial=-1;

    for(i=0; i<MAX; i++)
    {
        valores[i]=valorinicial;
        valoresb[i]=valorinicial;
        }
}

void cargarArreglos(int *A, int *B){
int i,j;

        printf("Cargue el primer arreglo");
            for (i=0;i<MAX ; i++ )
            scanf("%d", &A[i]);

        printf("cargue el segundo arreglo");
            for (j=0;j<MAX;j++ )
            scanf("%d",&B[j]);

}

void mostrar(int *c){

int i=0;
    for (i=0;i<MAX2 ;i++ ){
      printf("valor = %d\n", c[i]);
    }

}



void juntarArreglos(int *A, int *B){

int i1=0;
int i2=0;
int cont=0;
int C[MAX2];

    for(i1=0;i1<MAX && i2<MAX;cont++){
        if(A[i1]<B[i2]){
            C[cont]=A[i1];
            i1++;
            }else{
            C[cont]=B[i2];
            i2++;
            }
        }


    for(i1=0 ;i1<MAX;i1++)
            C[cont]=A[i1];
            cont++;
    for(i2=0 ;i2<MAX;i2++)
            C[cont]=B[i2];
            cont++;

    mostrar(C);

}

[Click_here]

with loop it'll be like this:

 int A[5]={1,3,5,7,9}, B[]={2,4,6,8,10}, C[10];

int count=0;

for(int i=0;i<5;i++)

    {

        C[i]=A[i];

        count++;

    }

for(int i=0;i<5;i++)

    {

        C[count]=B[i];

        count++;

    }


for(int i=0;i<10;i++)

   {

       printf("%d ",C[i]);

   } 

After merging you can do the sorting using any sorting algorithm, hopefully you'll be able to do that.

You shouldn't give away answers like that.

You can use recursion if you want to, but using a loop would be a better solution.

[AndiPersti]

well, finish the code.

How did you test it?

$ ./foo
Cargue el primer arreglo1 2 3 4 5
cargue el segundo arreglo6 7 8 9 10
valor = 1
valor = 2
valor = 3
valor = 4
valor = 5
valor = 5
valor = 10
valor = 0
valor = 3882996
valor = -1080235202

You have a buffer overflow in juntarArreglos():

void juntarArreglos(int *A, int *B){

int i1=0;
int i2=0;
int cont=0;
int C[MAX2];

    for(i1=0;i1<MAX && i2<MAX;cont++){
        if(A[i1]<B[i2]){
            C[cont]=A[i1];
            i1++;
            }else{
            C[cont]=B[i2];
            i2++;
            }
        }


    for(i1=0 ;i1<MAX;i1++)
            C[cont]=A[i1];
            cont++;
    for(i2=0 ;i2<MAX;i2++)
            C[cont]=B[i2];
            cont++;

There are two problems with your algorithm.
1) You assume A and B are already sorted.
2) After you filled up the new array C until one of either A or B is exhausted, you again add all elements from both A and B to C which causes the buffer overflow. (Hint: should you set both "i1" and "i2" back to 0?)

I suggest you reread grumpy's post and try to implement that algorithm (i.e don't mix the merging with the sorting).

I can do it with recursion?? the juntarArreglos function??

I'm not sure what you mean but there are several sorting algorithms like mergesort and quicksort which use recursion.

Bye, Andreas

[Gordo Miguel]

Click_here i test that answer, but doesnt work like i want.

AndiPersti in my pc works fine, but i recognize the mistake, i will study a little more

Thanx!