>>721
#include <stdio.h>

void disp( char *mes, int a[], int len ) {
int i;

puts( mes );
for ( i=0; i<len; i++) printf("a[%d]=%d\n", i, a[i] );
}
int max_index( int a[], int len ) {
int i, m=0 ;

for ( i=1; i<len; i++ ) if ( a[m] < a[i] ) m= i ;
return m ;
}
int array_sort( int a[], int n ) {
int i, m, work ;

for ( i=n-1; i>1; i-- ) {
m= max_index( a, i ) ;
if ( i != m ) { work= a[m] ; a[m]= a[i] ; a[i]= work ; }
}
}
int main() {
int a[]= { 5, 9, 6, 3, 4 } ;
int n= sizeof( a ) / sizeof( a[0] ) ;

disp( "before", a, n );
array_sort( a, n ) ;
disp( "after", a, n ) ;
}