text: //
  // Created by suncx on 2020/3/20.
  //
  #include <iostream>
  #include <vector>
  
  using namespace std;
  
  int main(int argc, char *argv[]) {
  
      vector<int> c;
      c.reserve(1024);
  
      c.push_back(1);
      c.push_back(2);
      c.push_back(3);
      c.push_back(4);
  
      for (auto it = c.begin(); it != c.end(); it++) {
          if (*it == 3) c.erase(it--);
      }
  
      for (auto i:c) {
          cout << i;
      }
  
      return 0;
  }