#include <stdio.h>

char	*get_complement(char *str);

main()
{
	char	*str;

	str = "acgtaaccggttatgctata";
	printf("%s\n", str);
	printf("%s\n", get_complement(str));
}


char	*get_complement(char *str)
{
	static char
		result[100];
	char	ch;
	int	i, j, len;

	len = strlen(str);
	j = 0;
	for (i = 0; ; i++) {
		if(*(str+i) == '\0')
			break;
		ch = *(str+(len-i-1));
		switch(ch){
		case 'a': ch = 't'; break;
		case 'A': ch = 'T'; break;
		case 'g': ch = 'c'; break;
		case 'G': ch = 'C'; break;
		case 'c': ch = 'g'; break;
		case 'C': ch = 'G'; break;
		case 't': ch = 'a'; break;
		case 'T': ch = 'A'; break;
		}
		result[j++] = ch;
	}
	result[j] = '\0';
	return(result);
}

                                                                               
#include <stdio.h>

char	*trans_tbl[4] = {
	 	"FFLLSSSSYY**CC*WLLLLPPPPHHQQRRRRIIIMTTTTNNKKSSRRVVVVAAAADDEEGGGG",
		"TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG",
		"TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG",
		"TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG"
	};


char	*get_complement(char *str);

main()
{
	char	*str, *seq;
	int	i1;
	char	cno1, cno2, cno3;
	int	conv;

	str = "acgtaaccggttatgctata";
	printf("%s\n", str);
	seq = get_complement(str);

	for(;;){
		cno1 = *seq;
		cno2 = *(seq+1);
		cno3 = *(seq+2);
		if(cno1 == '\0' || cno2 == '\0' || cno3 == '\0')
			break;

		if(cno1 >= 'a' && cno1 <= 'z'){
			cno1 = cno1 - 'a' + 'A';
		}
		if(cno2 >= 'a' && cno2 <= 'z'){
			cno2 = cno2 - 'a' + 'A';
		}
		if(cno3 >= 'a' && cno3 <= 'z'){
			cno3 = cno3 - 'a' + 'A';
		}
		conv = '*';
		for(i1 = 0; i1 < 64; i1++){
			if(trans_tbl[1][i1] == cno1 &&
			   trans_tbl[2][i1] == cno2 &&
			   trans_tbl[3][i1] == cno3){
				conv = trans_tbl[0][i1];
				break;
			}
		}
		putchar(conv);
		seq += 3;
	}
}


char	*get_complement(char *str)
{
	static char
		result[100];
	char	ch;
	int	i, j, len;

	len = strlen(str);
	j = 0;
	for (i = 0; ; i++) {
		if(*(str+i) == '\0')
			break;
		ch = *(str+(len-i-1));
		switch(ch){
		case 'a': ch = 't'; break;
		case 'A': ch = 'T'; break;
		case 'g': ch = 'c'; break;
		case 'G': ch = 'C'; break;
		case 'c': ch = 'g'; break;
		case 'C': ch = 'G'; break;
		case 't': ch = 'a'; break;
		case 'T': ch = 'A'; break;
		}
		result[j++] = ch;
	}
	result[j] = '\0';
	return(result);
}