пары

#include <algorithm>
#include <utility>
#include <fstream>
#include <vector>
#include <math.h>

using namespace std;


bool diag (pair<int,int> a)
{
    return (a.second == a.first);
}

bool eq(pair<int,int> a, pair <int, int> b)
{
    return a.first < b.first;
}

}
bool comp (pair<int,int> a)
{
    return (a.first > 0 && a.second < 0);
}
bool comparator(pair <int,int> a, pair <int, int> b)
{

    return ( a.first * a.first + a.second * a.second <  b.first * b.first + b.second * b.second ) ;
}


int main()
{
    ifstream in("input.txt");
    ofstream out("output.txt");

    vector <pair<int, int>> vec;
    int n;
    int m;
    while(in.peek() != EOF)
    {
        in >> n>> m;
        vec.push_back(make_pair(n, m));
    }
    vec.erase(remove_if(vec.begin(), vec.end(),comp), vec.end());
    for(int i = 0; i < (int) vec.size(); i++)
        out << "(" << vec[i].first << ", " << vec[i].second << ")"<< endl;
    out << " count of points on x=y: " << count_if(vec.begin(),vec.end(),diag);
    for_each
    sort(vec.begin(), vec.end(), eq);
    for(int i = 0; i < (int) vec.size(); i++)
        out << "(" << vec[i].first << ", " << vec[i].second << ")"<< endl;
    return 0;
}