return the minimum of three int's in function doesn't return anything

Question

I would like to return the minimum of three given numbers like this.

I don't know why it doesn't return anything

#include <stdio.h>

int minimum3(int un, int deux , int trois)
{
  int minimum;
    if (un<deux && un <trois)
        minimum= un;
    else if (deux<trois && deux<un)
        minimum= deux;
    else if (trois<deux && trois<un )
        minimum= trois;
  return minimum;
}

int main(void) {
  minimum3(4,88,8999);
  return 0;
}

Answer 1

As others mentioned in the comments, you ignore the returned value, a quick fix for that would be:

int main(void) {
  int min = minimum3(4,88,8999);

  printf("min: %d\n",min);

  return 0;
}

Despite that, your algorithm isn't that effective, as Jonathan mentioned, if 2 of the numbers you process are equal, there is no way to calculate the minimum. The better would,imo, would be to have another function that calculates the minimum of 2 numbers and then use that to compare to the third number. Much cleaner this way.

#include <stdio.h>

int min2(int a,int b)
{
    return ((a <= b) ? a : b);
}

int min3(int a,int b,int c)
{
    int mintmp = 0;

    mintmp = min2(a,b);

    return ((mintmp  <= min2(mintmp,c)) ? mintmp : min2(mintmp,c));
}

int main(void)
{
    printf("%d\n",min2(5,10));

    printf("%d\n",min3(5,-1,1));

    return 0;
}

You can of course replace the conditional expressions with simpler if else .