在C ++中将txt文件排序为矢量

Question

hey guys i have a c++ question.

im trying to write a program that will open and read a txt file of numbers and names such as: "9 john 3 jane 7 tom 2 sam 6 tom 1 nicole 5 tom 4 jane 8 ben"

once ive read the file i need to place the names in a vector in order of the numbers assigned to them. so when i print the vector it should be in this order:

nicole

sam

jane

jane

tom

tom

tom

ben

john

then i need to take the sorted vector and place the names in a new file with the number of times each name occurs. so when i print this new file the output should look like this:

nicole 1

sam 1

jane 2

tom 3

ben 1

john 1

so far this is my code: (ignore the count_names function as i was only using it to test my output) (i will need to do a recursive function later on so ignore any #include that i do not need at the moment)

using namespace std;

void fill_vector ( vector<string> &v );

void print_vector ( vector<string> v );

int count_names ( vector<string> v );

int main()
{

    vector<string> v;
    string s;

    fill_vector(v);

    int num_names;
    num_strings = count_strings(v)/2;
    cout << "number of names " << num_names << endl;

    print_vector(v);

    return 0;

}

void fill_vector ( vector<string> &v )
{
    string s;

    ifstream fin;
    string input = "toy_names.txt";
    fin.open ( input.c_str() );
    fin >> s;

    while ( !fin.eof() )
    {
        v.push_back ( s );
        fin >> s;
    }
}

void print_vector ( vector<string> v )
{

    for ( int i = 0; i < v.size(); i++ )
        cout << v[i] << endl;
}

int count_names ( vector<string> v )
{

    int counter = 0;
    for ( int i = 0; i < v.size(); i++ )
    {
        counter++;
    }

    return counter;
}

so as of right now this is my output:

9

john

3

jane

7

tom

2

sam

6

tom

1

nicole

5

tom

4

jane

8

ben

so i need help getting them into the proper order (the names in order of the number before them) and then writing them to the new txt file thanks

Answer 1

您可以执行std::vector<std::pair<int, std::string>>并仅使用std::sort(<yourvec>.begin(), <yourvec>.end()对您的成员进行排序。要创建一个std::pair<int, std::string> ，请使用您的数字以及与之链接的名称来调用构造函数。

Answer 2

If the numbers are unique, put the numbers and names into a std::map<int, std::string> . While you are at it, count the occurrences of each name in a std::map<std::string, unsigned int> .