列出九宫格输入组合

题目：列出九宫格键盘输入的所有字母组合

思路：将字母的组合看成k进制的数，列出字母组合的过程即为对数进行加法运算。

#include 
#include 
#include 

char* letter[] = {"abc","def","ghi","jkl","mno","pqrs","tuv","wxyz"};

void listAll(char* input)
{
	int len = strlen(input);
	int total = 1;
	int i;
	for ( i=0; i