用vector打印乘法口訣表

打印效果：

#include <iostream>
#include <vector>
#include <iomanip>
using namespace std;

int main(){
	int j = 0;
	vector<vector<int> >vec(9, vector<int>(0));
	for (int i = 0; i < 9; i++){
		for (j = 0; j <= i+1; j++){
			vec[i].push_back((i+1)*(j+1));
		}
	}

	for (int i = 0; i < vec.size(); i++){
		for (int j = 0; j <= i; j++){
			//使用setw(n) 進行格式控制
			cout << (i+1) << "*" << (j+1) << "=" << setw(2) << vec[i][j]<< " ";
			//printf("%d*%d=%2d ", (i+1),(j+1),vec[i][j]);
		}
		cout << endl;
	}
	return 0;
}