C++中String类的字符串分割实现

阳光穿透心脏的1/2处 2022-04-24 10:32 462阅读 0赞

C++中的string的常用函数用法总结  
[https://blog.csdn.net/qq\_37941471/article/details/82107077][https_blog.csdn.net_qq_37941471_article_details_82107077]

**利用strtok库函数切割字符串**

#pragma warning(disable:4996)
    #include<iostream>
    #include<vector>
    #include<string>
    using namespace std;
    
    int main()
    {
    	string str;
    	cin >> str;
    	
    	char *split = "+-";//23+86-6+37+24-8-13
    
    	//string转char *。c_str()是string转const char *
    	char *tempStr = new char[str.size()];
    	//#pragma warning(disable:4996)
    	str.copy(tempStr, str.size(), 0); //这里5，代表复制几个字符，0代表复制的位置
    	*(tempStr + str.size()) = '\0'; //要手动加上结束符
    									
    	vector<int> nums;
    
    	char *p2 = strtok(tempStr, split);
    	while (p2 != NULL)
    	{
    		nums.push_back(stoi(p2));//cout << p2 << endl;
    		p2 = strtok(NULL, split);
    	}
    
    	for (int i = 0; i < nums.size(); i++)
    		cout << nums[i] << " ";
    
    	cout << endl;
    	return 0;
    }

输入：23+86-6+37+24-8-13  
输出：23 86 6 37 24 8 13

**自我总结**：

**//定义好输入输出接口**

void mySplit(const string& inStr, vector<string>& outStr,char *split)
    {
    	/*此代码之下为切割*/
    	//char *split = "+-";//23+86-6+37+24-8-13
    
    	//string转char *。c_str()是string转const char *
    	char *tempStr = new char[inStr.size()];
    	//#pragma warning(disable:4996)
    	inStr.copy(tempStr, inStr.size(), 0); //这里5，代表复制几个字符，0代表复制的位置
    	*(tempStr + inStr.size()) = '\0'; //要手动加上结束符
    
    	char *p2 = strtok(tempStr, split);
    	while (p2 != NULL)
    	{
    		outStr.push_back(p2);
    		//cout << p2 << endl;
    		p2 = strtok(NULL, split);
    	}
    	/*此代码之上为切割*/
    }

#pragma warning(disable:4996)
    #include<iostream>
    #include<vector>
    #include<string>
    using namespace std;
    
    //定义好输入输出接口
    void mySplit(const string& inStr, vector<string>& outStr,char *split)
    {
    	/*此代码之下为切割*/
    	//char *split = "+-";//23+86-6+37+24-8-13
    
    	//string转char *。c_str()是string转const char *
    	char *tempStr = new char[inStr.size()];
    	//#pragma warning(disable:4996)
    	inStr.copy(tempStr, inStr.size(), 0); //这里5，代表复制几个字符，0代表复制的位置
    	*(tempStr + inStr.size()) = '\0'; //要手动加上结束符
    
    	char *p2 = strtok(tempStr, split);
    	while (p2 != NULL)
    	{
    		outStr.push_back(p2);
    		//cout << p2 << endl;
    		p2 = strtok(NULL, split);
    	}
    	/*此代码之上为切割*/
    }
    
    int main()
    {
    	string str;
    	cin >> str;
    
    	vector<string> outStr;
    	mySplit(str, outStr, ",");
    	for (int i = 0; i < outStr.size(); i++)
    			cout << outStr[i] << " ";
    	cout << endl;
    	return 0;
    }

输入：11,22,3,45,56,77,88,9,0  
输出：11 22 3 45 56 77 88 9 0

string str;
    cin >> str;
    vector<string> outStr;
    mySplit(str, outStr, "[,]");
    for (int i = 0; i < outStr.size(); i++)
    	cout << outStr[i] << " ";
    cout << endl;

输入：\[0,2,3,0,5,6\]  
输出：0 2 3 0 5 6

转：[https://www.cnblogs.com/carsonzhu/p/5859552.html][https_www.cnblogs.com_carsonzhu_p_5859552.html]  
1.简洁高效的方法（不过只能包含一个分隔符）：

#include <vector>
    #include <string>
    #include <iostream>
    using namespace std;
    
    void SplitString(const string& s, vector<string>& v, const string& c)
    {
    	string::size_type pos1, pos2;
    	pos2 = s.find(c);
    	pos1 = 0;
    	while (string::npos != pos2)
    	{
    		v.push_back(s.substr(pos1, pos2 - pos1));
    
    		pos1 = pos2 + c.size();
    		pos2 = s.find(c, pos1);
    	}
    	if (pos1 != s.length())
    		v.push_back(s.substr(pos1));
    }
    
    int main() {
    	string s = "aa,bb,cc,dd,ee,ff";
    	vector<string> v;
    	SplitString(s, v, ","); //可按多个字符来分隔;
    	for (vector<string>::size_type i = 0; i != v.size(); ++i)
    		cout << v[i] << " ";
    	cout << endl;
    	//输出: aa bb cc dd ee ff
    }

2.可包含多个分隔符的实现方式

#include <vector>
    #include <string>
    #include <iostream>
    using namespace std;
     
    vector<string> split(const string &s, const string &seperator){
        vector<string> result;
        typedef string::size_type string_size;
        string_size i = 0;
         
        while(i != s.size()){
            //找到字符串中首个不等于分隔符的字母；
            int flag = 0;
            while(i != s.size() && flag == 0){
                flag = 1;
                for(string_size x = 0; x < seperator.size(); ++x)
                    　　if(s[i] == seperator[x]){
                        　　++i;
                        　　flag = 0;
                        　　 break;
                        　　}
            }
             
            //找到又一个分隔符，将两个分隔符之间的字符串取出；
            flag = 0;
            string_size j = i;
            while(j != s.size() && flag == 0){
                for(string_size x = 0; x < seperator.size(); ++x)
                    　　if(s[j] == seperator[x]){
                        　　flag = 1;
                        　　 break;
                        　　}
                if(flag == 0)
                    　　++j;
            }
            if(i != j){
                result.push_back(s.substr(i, j-i));
                i = j;
            }
        }
        return result;
    }
     
    int main(){
    //  string s = "a,b*c*d,e";
        string s;
        getline(cin,s);
        vector<string> v = split(s, ",*"); //可按多个字符来分隔;
        for(vector<string>::size_type i = 0; i != v.size(); ++i)
            cout << v[i] << " ";
        cout << endl;
        //输出: a b c d e
    }

[https_blog.csdn.net_qq_37941471_article_details_82107077]: https://blog.csdn.net/qq_37941471/article/details/82107077
[https_www.cnblogs.com_carsonzhu_p_5859552.html]: https://www.cnblogs.com/carsonzhu/p/5859552.html