trpo

#include<iostream>
#include<vector>
#include<fstream>
#include<string>
#include<sstream>

using namespace std;

template <typename T>
int partition(vector<T>& V, int low, int high){
    T pivot = V[floor((high + low)/2)];

    int i = low;
    int j = high;
    while (true) {

        while (V[i] < pivot) {
            i++;
        }

        while (V[j] > pivot) {
            j--;
        }

        if (i >= j) return j;

        swap(V[i++], V[j--]);
    }
}

template <typename T>
void quicksort(vector<T> &V, int low, int high){

    if (low < high)
    {
        T pivot = partition(V, low, high);

        quicksort(V, low, pivot);
        quicksort(V, pivot+1, high);
    }
    return;
}

bool isNumber(const string& str) {
    return str.find_first_not_of("-.,0123456789") == string::npos;
}

template <typename T>
string parsStream(vector<T>& V, ifstream& input ) {

    string delimiter = " ";
    string token;
    T buf;

    while (getline(input, token, ' ')) {
        if (isNumber(token))
        {
            stringstream string_s(token);
            string_s >> buf;
            V.push_back(buf);
        }

        else return token;
    }
    return "";
}

template <typename T>
void printSequence(const vector<T>& V) {
    for (int i = 0; i < V.size(); i++) {
        cout << V[i] << " ";
    }
    cout << endl;

}




int main() {

    ifstream FILE;
    //vector<int> V = { 12,3,4,5,6,78,0 };

    vector<int> V;

    string buf;

    FILE.open("input.txt");

    buf = parsStream(V, FILE);

    FILE.close();

    if (V.size() == 0) {
        cout << "File contains no elements" << endl;
        return -1;
    }

    if (buf != "") {
        cout << "File contains characters other than numbers: " << buf << endl;
        return -1;
    }

    cout << "Unsorted sequence from file" << endl;
    printSequence(V);

    quicksort(V, 0, V.size()-1);

    cout << "Sorted sequence from file" << endl;
    printSequence(V);

    return 0;
}