>>707 (2) あ〜〜〜もうだりぃ。
#include <iostream>
using namespace std;
int main() {
double a;
cout << "倍精度浮動小数点で数値を入力 > ";
cin >> a;
cout << "切り捨て" << (int)a <<endl;
cout << "切り上げ" << (int)(a+0.9) <<endl;
cout << "四捨五入" << (int)(a+0.5) <<endl;
return 0;
}