Union as status parameter in C

Today's problem is on the declaration of a union structure with members of all datatypes.  When program computes a problem, it updates the union members and shows the output exactly in the same format, as the union members were updated. 

I wrote a C program for the same problem. The C codes are given below:

#include <stdio.h>

#include <string.h>

union out {

    int ansi;     //for integer type answer

    float ansf;     //for float type answer

    double ansd;     //for double type answer

    char *anss;     //for char type answer

};

void outv(union out *s, int i) { //output function

    if (i == 0 || i == 1) //convert all numeric data into double type

        printf("%lf\n", s->ansd);

    if (i == 3) //for string type output

        printf("%s\n", s->anss);

    return;

}

int main() {

    union out o;

    double i = 0, j = 0;

    double ans;

    printf("Enter two space separated numbers : ");

    scanf("%lf", &i);

    scanf("%lf", &j);

    if (i == 0 && j == 0) { //check all numbers should not be zeros

        o.anss = "All number are zero. Not Accepted.";

        outv(&o, 3); //push string output

        return 0;

    }

    ans = i + j;

    o.ansd = ans;

    outv(&o, 0); //push numeric output

    if (j == 0) { //check whether denominator is zero

        o.anss = "Division by zero. Not Accepted.";

        outv(&o, 3); //push string output

        return 0;

    }

    ans = i / j;

    o.ansd = ans;

    outv(&o, 1); //push numeric output

    return 0;

}