输入与输出

1. cout的setprecision头文件：#include<iomanip>

cout<<setprecision(1)<<fixed<<"T "<<num1<<" D "<<num2<<" H "<<calc_h(num1,num2)<<endl;

2. printf打印double，用%f，printf("%.2f",num1);

scanf输入double，用%lf，scanf("%lf",&num1);

3. cin，cout因为同步会比scanf，printf慢

解决方式，在main函数里加上

ios::sync_with_stdio(false);

4. cout打印数字固定宽度

cout<<setw(20)<<table[j].x<<" "<<setw(20)<<table[j].y<<" "<<setw(20)<<table[j].z<<" "<<table[j].i<<endl;