Split String [3 different ways]

//none made ​​by me

#include <cstring>
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <iterator>

int main()
{

    //1
    char input[100] = "A bird came down the walk";
    char *token = std::strtok(input, " ");
    while (token != NULL) {
        std::cout << token << '\n';
        token = std::strtok(NULL, " ");
    }

    //2

    std::string str = "This is a string";
    std::istringstream buf(str);
    std::istream_iterator<std::string> beg(buf), end;

    std::vector<std::string> tokens(beg, end); // done!

    for(auto& s: tokens)
        std::cout << '"' << s << '"' << '\n';

    //3

    std::string s = "scott>=tiger>=mushroom";
    std::string delimiter = ">=";

    size_t pos = 0;
    std::string ttoken;
    while ((pos = s.find(delimiter)) != std::string::npos) {
        ttoken = s.substr(0, pos);
        std::cout << ttoken << std::endl;
        s.erase(0, pos + delimiter.length());
    }
    std::cout << s << std::endl;

}