视频解析

抖音

#include <iostream>//关注b站海绵经验包
#include <iomanip>
using namespace std;
int main() {
  double b;
  cin >> b;
  cout << (int)a << endl;
  cout << fixed << setprecision(2) << a << endl;
  cout << fixed << setprecision(？) << a << endl;
  return 0;
}