3rd problem

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

unsigned addnum(unsigned x[],unsigned y[],unsigned z[])
{
        unsigned max,i;
        unsigned carry=0;
        if (x[0]>y[0])
            max=x[0];
        else max=y[0];
        for (i=1;i<=max;i++)
        {
            z[i]=(x[i]+y[i]+carry)%10;
            carry=(x[i]+y[i]+carry)/10;
        }
        if (carry!=0)
        {
            z[i]=carry;
            z[0]=max+1;
        }
        else z[0]=max;
        return z[0];
}



int main()
{
    unsigned x[7]={3,7,1,3},y[7]={4,4,2,9,9},z[7]={0};
    printf("%u\n",addnum(x,y,z)); // should be 5 for x[7]={3,7,1,3},y[7]={4,4,2,9,9},z[7]={0}

    for (int i=5;i>=1;i--)
        printf("%u",z[i]); // should be 10241 for x[7]={3,7,1,3},y[7]={4,4,2,9,9},z[7]={0}
    printf("\n");
    return 0;
}