粤菜高端菜:简单C++找错,谢谢。

//========================
//f0311.cpp
//若干个向量按长短排序
//========================
#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;
//-------------------------
typedef vector <vector<int>> Mat;
Mat input();
void mySort (Mat& a);
void print (const Mat& a);
//-------------------------
int main()
[
Mat a=input();
mySort(a);
print(a);
}//------------------------
Mat input()
{
ifstream in("aaa.txt");
Mat a;
for (string s;getline(in,s);)
{
vector<int> b;
istringstream sin(s);
for (int ia;sin>>ia;)
b.push_back(ia);
a.push_back(b);
}
return a;
}
//-------------------------
void mySort(Mat &a)
{
for (int pass=1;pass<a.size();++pass)
for (int i=0;i<a.size()-pass;++i)
if (a[i+1].size() < a[i].size())
a[i].swap(a[i+1]);
}
//-------------------------
void print(const Mat &a)
{
for (int i=0;i<a.size();++i)
{
for (int j=0;j<a[i].size();++j)
cout<<a[i][j]<<" ";
cout<<endl;
}
}
//=========================