4.21

#include<iostream>
using namespace std;
int main()
{
int **a;
int row,col,i,j;
cout<<"请输出矩阵的行数和列数:";
cin >> row >> col;
a = new int*[row];
for(i=0;i<row;i++)
*(a+i)=new int[col];
cout<<"请输出"<<row<<"行"<<col<<"列矩阵:"<<endl;
for(i=0;i<row;i++)
for(j=0;j<col;j++)
cin >> a[i][j];
cout<<"矩阵的转置为:"<<endl;
for(j=0;j<col;j++)
{
for(i=0;i<row;i++)
cout<<a[i][j]<<"";
cout<<endl;
}
for(i=0;i<row;i++)
delete[] a[i];
delete[] a;
}