輸入輸出

#include <bits/stdc++.h>
using namespace std;
int main(){
	//保留3位有效數字？(四捨五入)-> cout 
	cout<<setprecision(3)<<3.004<<endl;
	//精確小數點後三位(四捨五入) -> cout
	cout<<fixed<<setprecision(3)<<3.0135<<endl;
	//精確小數點後三位(四捨五入) -> printf
	//int %d float %f double %lf char %c string %s
	printf("%1.3f\n%1.3f\n%s",3.0015,3.0049,"45612348");
	cout<<1111<<"\n"<<2222;//\n 換行符 
	return 0;
}