Returning structure containing int array from Structure Function

Question

main function is not printing same o/p as structure function Why?

or

memcpy is not copying whole array

please help.

expected o/p

7 4 5 6 2

7 4 5 6 2

but

getting o/p

7 4 5 6 2

7 4 garbage garbage garbage

thanks in advance.

#include <stdio.h>
#include <string.h>
struct Result {
    int output[100];
};

struct Result my(int length, int path, int input[]){
    int temp=input[path-1];
    for(int i=path-1; i>0; --i){
        input[i]=input[i-1];
        }
        input[0]=temp;

        for (int i = 0; i <= length; i++) {
            printf(" %d",input[i]);
        }

        struct Result result;
        memcpy (result.output, input, sizeof(strlen(input)));
    return result;
}

int main(void){
    int a[]={4,5,6,7,2};
    struct Result res = my(4,4,a);

    printf("\n");

    for (int i = 0; i <= 4; i++) {
        printf(" %d",res.output[i]);
    }
return 0;
}

Answer 1

Two problems.

1. You cannot use strlen for int array.
2. memcpy needs number of bytes to be copied.

Hence change

 memcpy (result.output, input, sizeof(strlen(input)));

to

  memcpy (result.output, input, sizeof(input[0])*(length+1)); //length+1 since your passing array length-1

Note: sizeof(input) is sizeof(pointer) when array is passed as parameter to function.