形如vector<vector<int>>怎麼初始化：

輸入m,n

m為vector<int>個數

n每個vector中的元素

#include<iostream>
#include<vector>

using namespace std;

int main()
{
	int m,n;
	cout<<"m=";
	cin>>m;
	cout<<"n=";
	cin>>n;//m個vector<int> 每個vector有n個元素 

	vector<vector<int> > ivec;

	for(int i=0;i<m;++i)
	{
		vector<int> vec;
		cout<<"Input "<<n<<" numbers at "<<i+1<<" times"; 
		for(int j=0;j<n;++j)
		{
			int x;//每一個元素
			cin>>x;
			vec.push_back(x);
		}
		ivec.push_back(vec);
	}

	for(int i=0;i<m;++i)
	{
		cout<<"The "<<i+1<<"th output is:"; 
		for(int j=0;j<n;++j)
			cout<<ivec[i][j]<<" ";
		
		cout<<endl;
	}
}