Swapping the greatest value and smallest value in Array

/*
Element of Array before swapping::

a[0] = 3
a[1] = 18
a[2] = 7
a[3] = 5
a[4] = 20
maximum is 20

position of greatest no is 20 is a[4]
position of smallest no is 3 is a[0]
a[0]==20
a[1]==18
a[2]==7
a[3]==5
a[4]==3

*/
#nclude<stdio.h>
#include<conio.h>
    void swap(int*, int*);
int a[] = {3,18,7,5,20};
int i,j,k=0,l=0,max,min,pos_max,pos_min;

void main()
{
clrscr();
printf("\nElement of Array before swapping::\n");
for(i=0;i<5;i++)
printf("\na[%d] = %d",i,a[i]);

max=a[0];
for(i=0;i<5;i++)
{
if(a[i]>max)
{
max=a[i];
}
}
printf("\nmaximum is %d\n", max);

for(i=0;i<5;i++)
{
if(max==a[i])
{
pos_max=i;
printf("\nposition of greatest no is %d is a[%d]",max,pos_max);
}
}

min=a[0];
for(i=0;i<5;i++)
{
if(a[i]<min)
{
min=a[i];
}
}

for(i=0;i<5;i++)
{
if(min==a[i])
{
pos_min=i;
printf("\nposition of smallest no is %d is a[%d]",min,pos_min);
}
}


swap(a+pos_max, a+pos_min);

for(i=0;i<5;i++)
printf("\na[%d]==%d",i,a[i]);
getch();
}

void swap(int *t,int *u)
{
int temp=*t;
*t=*u;
*u=temp;
}