字符串截取

代码：

#include <iostream>
#include<vector>
#include<string>
#include<algorithm>
using namespace std;
int main()
{   
    string patter =", .";
    string source ="Hello world, i said hello world to the world";
    transform(source.begin(),source.end(),source.begin(),tolower);
    vector<string> result;
    int size = source.size();
    int i = 0;
    for(;i < size;i++)
    {
        auto found = source.find_first_of(patter,i);
        if(found != string::npos)
        {
            result.push_back(source.substr(i,found-i));
            i = found;
        }
        else
            break;
    }
    if(i != size-1)
    {
        result.push_back(source.substr(i));
    }
    for(int i =0;i < result.size();++i)
    {
        cout<<result[i];
    }
    cout<<endl;
}