c++ - insert performance sort data in list and vector -

in principle , practice book of bjarne stroustrup there exercise in chapter 20 asks insert random value in vector , list in sort way (experiment suggested jhon bentley)

this code (if there better way doing sorry )

#include <vector> #include <list> #include <iostream> #include <ctime> #include <random> #include <chrono> using namespace std;   template<typename iter, typename t> int find_index(iter start, iter end, const t& value) {     int index = 0;     while (start != end)     {         while (start!=end && value >= *start)         {             ++index;             ++start;         }         return index;     }     return -1; }  template<typename iter> void print(iter first,iter end) {      while (first != end)     {         cout << *first << endl;         first++;     } }  int generate_random(int min, int max) {     random_device device;     mt19937 generator{ device() };     uniform_int_distribution<int> d{ min,max };     return d(generator); }  int main() {     int n = 1000;      vector<int> vec;     list<int> list;      auto start = chrono::system_clock::now();     (size_t = 0; i<n; i++)     {         int value = generate_random(1, n);         int index = find_index(vec.begin(), vec.end(), value);         if (index == -1) vec.insert(vec.begin(), value);         else vec.insert(vec.begin() + index, value);     }     auto end = chrono::system_clock::now();     print(vec.begin(), vec.end());     cout << "time: " << chrono::duration_cast<chrono::milliseconds>(end - start).count() << " milliseconds" << endl;     system("pause");      start = chrono::system_clock::now();     (size_t = 0; < n; i++)     {          int value = generate_random(1, n);         int index = find_index(list.begin(), list.end(), value);         if (index == -1) list.insert(list.begin(), value);         else         {             auto p = list.begin();             (size_t = 0; < index; i++)             {                 p++;             }             list.insert(p, value);         }     }     end = chrono::system_clock::now();     print(list.begin(), list.end());     cout << "time: " << chrono::duration_cast<chrono::milliseconds>(end - start).count() << " milliseconds" <<  endl;      system("pause"); } 

and output is:

n     1000     5000     10000     100000 vec   250ms    4s       16s       laptop committed suicide list  600ms    15s      63s       laptop committed suicide 

---

vec fast list why book says: << performance reasons, wouldn't use insert , erase int middle of 100000 element vector; list (and map) better.>>
did write code in wrong way?