Merge two arrays (sorted) with no repetitions of values

mergeunique.cpp

#include <iostream>
using namespace std;

void merge_em_all(int *a, int *b, int *c, int x, int y, int z) {
    
    int i=0, j=0, k= 0;
    
    for(i=0, j=0; i<x && j<y; ) {
        
        if(a[i]< b[j]){
            c[k++]= a[i];
            a[i]=-1;
            i++;
        } else if(a[i]> b[j]) {
            c[k++]= b[j];
            b[j]=-1;
            j++;
        } else {
            c[k++]= a[i];
            a[i]=-1;
            b[j]=-1;
            j++;
            i++;
        }
    }
    int xx=0;
    while (xx< x){
        if(a[xx]!=-1)
            c[k++]= a[xx];
        xx++;
    }
    xx=0;
    while (xx< y){
        if(b[xx]!=-1)
            c[k++]= b[xx];
        xx++;
    }
    
}

int main() {
	int a[]= {2,4,5,6,7,9,13};
	int b[]= {2,3,4,7,8,10,12};
	int n1= sizeof(a)/sizeof(int);
	int n2= sizeof(b)/sizeof(int);
	int n3= n1+n2;
	int c[n3];
	merge_em_all(a,b,c,n1,n2,n3);
	for(int i=0; c[i]!='\0'; i++){ // \0 is null for all arrays
	    cout<<c[i]<<" ";
	}
	return 0;
}