字符串分隔

描述

给定一个字符串，-是分隔符 --或更多的---是分隔符，除了字母和数字外，其他的都是分隔符，将字符串分隔

输入

a--stu- he-ll0*-go--od * $@go-0d aaa

输出

a stu he-ll0 go od go-0d aaa

思路

题目要判断的条件比较多，用状态机做会清晰很多：

代码

#include <iostream>
#include <string>
#include <vector>

using namespace std;

#define WORD 0
#define ONE_SHOT 1
#define SPLIT 2

#define is_alpha(x) ((x>='a' && x<='z') || (x>='A'&&x<='Z') || (x>='0'&&x<='9'))

#define NEXT(str, i) ((i>=(str.size()-1)) ? 0 : str[i+1])

void split(string str, vector <string>& vec)
{
	int state;
	char next;
	int start, end;

	if(is_alpha(str[0])) {
		state = WORD;
		start = 0;
	} else {
		state = SPLIT;
	}

	for(int i=0; i<str.size();i++) {
		next = NEXT(str, i);

		switch(state) {
			case WORD: {
				if(next == 0) {
					end = i;
					vec.push_back(str.substr(start, end-start+1));
				} else if(is_alpha(next)) {
					state = WORD;
				} else if(next == '-') {
					state = ONE_SHOT;
					end = i;
				} else {
					state = SPLIT;
					end = i;
					vec.push_back(str.substr(start, end-start+1));
				}

				break;
			}

			case ONE_SHOT: {
				if(is_alpha(next)) {
					state = WORD;
				} else {
					state = SPLIT;
					vec.push_back(str.substr(start, end-start+1));
				}
				break;
			}

			case SPLIT: {
				if(is_alpha(next)) {
					state = WORD;
					start = i+1;
				} else {
					state = SPLIT;
				}
				break;
			}
		}
	}

	return;
}

int main(int argc, char **argv)
{
	string str1("*a--stu*- he-ll0*-go--od * $@go-0d   aaa");
	vector <string> vec;

	split(str1, vec);
	for(int i=0; i<vec.size(); i++) {
		cout << vec[i] << " ";
	}
	cout << endl;

	return 0;
}