I may have found the most inefficient way?

#include<stdio.h>

int main()
{
int a,b,c,d,ia,ib,ic,id, max, min;

 printf("Enter four integers:");
    scanf("%d %d %d %d", &a, &b, &c, &d);

ia=(a>b||a>c||a>d)-(a<b||a<c||a<d);
ib=(b>a||b>c||b>d)-(b<a||b<c||b<d);
ic=(c>b||c>a||c>d)-(c<b||c<a||c<d);
id=(d>b||d>c||d>a)-(d<b||d<c||d<a);

switch (ia)
{
case 1: max=a;
break;
case -1: min=a;
break;
default:
break;
}

switch (ib)
{
case 1: max=b;
break;
case -1: min=b;
break;
default:
break;
}

switch (ic)
{
case 1: max=c;
break;
case -1: min=c;
break;
default:
break;
}

switch (id)
{
case 1: max=d;
break;
case -1: min=d;
break;
default:
break;
}

    printf("Maximum: %d",max);
    printf("\nMinimum: %d",min);

return 0;
}