Why do while loop doesn't work correctly?

i write a C code to generate a random character and check if this character exists in an array if it exist i want to re-generate a new char . i'm used a fag as an indicator and used do{}while() loop to check this flag , but unfortunately code doesn't work as desired and i get a numbers already exist in the array : (
i need your help to understand and solve the problem .

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main()
{
    char c  ;
    int num ;
    int flag = -1 ;
    char temp[5] = { '3' , '2' , '5' ,'9' , '1' }  ;
    srand(time(NULL)) ;
    do{
        num = rand()%5 ;
        c = num ;
        for( int i = 0  ; i<5 ;  i++)
        {
            if(temp[i] == c )
            {
                flag = 0 ;
                break ;

            }
            else
            {
                flag = 1 ;
            }
        }

    }while(0==flag);

    printf("number is : %d\n" , c ) ;
    return 0 ;
}