Gerar inteiros randomicos nao repetidos c++

    #include <iostream>
    #include <stdlib.h>
    #include <stdio.h>
    //#include<conio.h>
    #include <time.h>
    using namespace std;

    int main() {

        int i = 0, j = 0, k = 0 ,va[10], vb[10], aux = 0;

            srand(time(NULL));
            for(i = 1; i <=10; i++)
            {
                va[i] = 1 + rand() % 20;
                for(j = 1; j<i;j++)
                {
                    if(va[i] == va[j])
                    {

                        i--;



                    }




                }



            }
            for(int i = 1; i <=10;i++)
                printf("\n%i",va[i],"\n");

        printf("\nVETOR");






        return 0;
    }