rank pick point

#include<iostream>
#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
template<typename T> using V=vector<T>;
template<typename T1,typename T2> using P=pair<T1,T2>;
int main(){
    fstream fin("input.txt",ios::in);
    fstream fout("output.txt",ios::out);
    V<int> v{0};
    V<P<int,double>> res;
    int n;
    while(fin>>n)
        v.emplace_back(n);
    int cur_cnt=0,cur_val=-1;
    for(int i=1;i<int(v.size());i++){
        if(cur_val!=v[i])
            cur_cnt=1,res.emplace_back(i-cur_cnt+cur_cnt/2.0,cur_val),cur_val=v[i];
        else
            cur_cnt++;
    }
    res.emplace_back(v.size()-cur_cnt+1+cur_cnt/2.0,cur_val);
    for(int i=1;i<int(res.size());i++)
        fout<<res[i].first<<'\t'<<res[i].second<<endl;
    return 0;
}