t9.c

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#define readline(buf) do {                                             \
		int j, c;                                              \
		for(j = 0; (c = getchar()) != '\n' && c != EOF; j++) { \
			buf[j] = c;                                    \
		}                                                      \
		buf[j] = '\0';                                         \
	} while(0)

#define readinput(input, output, n, limit, olimit) do {                    \
		char buf[8];                                               \
		int i;                                                     \
		readline(buf);                                             \
		n = atoi(buf);                                             \
		input = (char **)malloc(n * sizeof(char *));               \
		output = (char **)malloc(n * sizeof(char *));              \
		for(i = 0; i < n; i++) {                                   \
			input[i] = (char *)malloc(limit * sizeof(char));   \
			readline(input[i]);                                \
			output[i] = (char *)malloc(olimit * sizeof(char)); \
			output[i][0] = '\0';                               \
		}                                                          \
	} while(0)

void
free_streams(int length, int n, ...)
{
	char **v;
	int i, j;
	va_list st;
	va_start(st, n);
	for(i = 0; i < n; i++) {
		v = va_arg(st, char**);
		for(j = 0; j < length; j++) {
			free(v[j]);
		}
		free(v);
	}
	va_end(st);
}

int digits[26] = {
	2, 22, 222, 3, 33, 333, 4, 44, 444, 5, 55, 555,
	6, 66, 666, 7, 77, 777, 7777, 8, 88, 888, 9, 99,
	999, 9999,
};

void
t9(char **input, char **output, int n)
{
	int i, j, siz;
	char tmp[6], *t;
	for(i = 0; i < n; i++) {
		siz = strlen(input[i]);
		for(j = 0; j < siz; j++) {
			if(input[i][j] == ' ') {
				tmp[0] = ' ';
				tmp[1] = '0';
				tmp[2] = '\0';
			} else {
				sprintf(tmp, " %d", digits[input[i][j]-'a']);
			}
			t = tmp;
			if(output[i][strlen(output[i])-1] != t[1]) {
				t++;
			}
			strcat(output[i], t);
		}
	}
}

int
main(void)
{
	int i, n;
	char **messages, **output;
	readinput(messages, output, n, 1001, 5005);
	t9(messages, output, n);
	for(i = 0; i < n; i++) {
		printf("Case #%d: %s\n", i+1, output[i]);
	}
	free_streams(n, 2, messages, output);
}