[C++知识库]C/C++程序设计：打印九九乘法表（3 ways)

(1)
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
	cout<<setw(4)<<"*";
	for(int i=1;i++;i<=9)
		cout<<i<<endl;

/*	for(int k=1;k++;i<=9)
	{
		cout<<k;
		for(int j=1;j<=9;j++)
			cout<<i*j;
		cout<<endl;
	}*/
}



(2)
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
	cout<<setw(4)<<"*";
	for(int i=1;i<=9;i++)
		cout<<setw(4)<<i;
	cout<<"\n...........................................\n";


	for(int k=1;k<=9;k++)
	{
		cout<<setw(4)<<k;
		for(int j=1;/*j<=9*/j<=k;j++)//将j<=9更改成j<=k即可
			cout<<setw(4)<<k*j;
		cout<<endl;
	}
	cout<<endl;
}

(3)
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
	cout<<setw(4)<<"*";
	for(int i=1;i<=9;i++)
		cout<<setw(4)<<i;
	cout<<"\n...........................................\n";


	for(int k=1;k<=9;k++)
	{
		cout<<setw(4)<<k;
		if(k!=1)
			cout<<setw(4*k-4)<<" ";
		for(int j=k;j<=9;j++)//此时，J从k开始循环
			cout<<setw(4)<<k*j;
		cout<<endl;
	}
	cout<<endl;
}