#include<stdio.h>
extern void i_add(int ,char *);
extern void i_print(int);
extern void remove_root(void);

char *data[]={
"saf","fsf","fdg","lff","lfg",
"oko","uri","ori","ire","uiu","ooo",
"lll","nmn","hUh","III","UUU","YYY",
"PEO",
"dfs",
"dfcd"
};

main()
{
int i,n;

n=sizeof(data)/sizeof(char *);
for(i=1;i<=n;i++)
	i_add(i,data[i-1]);
for(i=1;i<=n;i++)
	i_print(i);
sort_heap(n);
for(i=1;i<=n;i++)
i_printf(i);
for(i=1;i<=n;i++){
i_print(1);
remove_root();
}
}

In function `main':
undefined reference to `i_add'
undefined reference to `i_print'
undefined reference to `sort_heap'
undefined reference to `i_printf'
undefined reference to `i_print'
undefined reference to `remove_root'