Question

Please help me, i’m stuck at this.
I have a function which must sum two arrays of integers of size n
and i must pass as arguments for the function the first element of each array
Is this enven close?

 12 void sumVect(int * v[], int * w[] ,int n)
 13 //adds the second vector to the first vector; the vectors v and w have exactly n components
 14 {
 15         int i;
 16         for(i=0;i<n;i++)
 17         {
 18                 *v[i]+=*w[i];
 19         }
 20 
 21 }

I will give you the whole code

#include <stdio.h>

void sumVect(int * v[], int * w[] ,int n)
//adds the second vector to the first vector; the vectors v and w have exactly n components
{
    int i;
    for(i=0;i<n;i++)
    {
        *v[i]+=*w[i];
    }

}


int main()
{   
    int i,j;
    int n = 4;  //the size of a vector
    int k = 5;  //the number of vectors
    int v[k][n];    //the vector of vectors

    printf("How many vectors? k=");
    scanf("%d",&k);

    printf("How many components for each vector? n=");
    scanf("%d",&n);

    for(i=1;i<=k;i++)   //read the content of each vector from the screen
    {
        printf("\nv%d   |\n_____|\n",i);

        for(j=0;j<n;j++)
        {
            printf("v%d[%d]=",i,j);
            scanf("%d", &v[i][j]);
        }
    }

    for(j=1;j<k;j++)
    {
        sumVect(&v[j], &v[j+1], n);
        for(i=0;i<n;i++)
        {
            printf("%d",v[j][i]);
        }
    }


    return 0;
}

Answer 1

Note that you are passing type int [] but your formal parameters in the function is int *[] . Therefore your signature should be:

void sumVect(int v[], int w[] ,int n)

or

void sumVect(int *v, int *w,int n)

Also you should access them in the function like

v[i] + w[i] because v and w both are int * or int [] (depends on the formal paremeter)

Also when calling you should do:

sumVect(v[j], v[j+1], n);

or

sumVect(&v[j], &v[j+1], n);

This is because as as v[j] is type of int [] , &v[i] and v[i] will evaluate to the same address.