对齐输入

#include <iostream>  
#include<iomanip>  
using namespace std;  
  
int main()  
{  
    int a = 9999;  
    int b = 999;  
    int c = 99;  
  
    //默认右对齐  
    cout << "默认右对齐为：\n";  
    cout << setw(4) << a << endl;  
    cout << setw(4) << b << endl;  
    cout << setw(4) << c << endl;  
  
    //现在改为左对齐  
    cout << "\n改为左对齐后为：\n";  
    cout << left << setw(4) << a << endl;  
    cout << left << setw(4) << b << endl;  
    cout << left << setw(4) << c << endl;  
  
    return 0;  
}  

输出对齐需要包含头文件<iomanip>，当然对齐方式也分为左右两种，直接看代码更好理解