最大子矩阵和问题

#include<iostream>
using namespace std;
//给定一个矩阵a(0...m-1,0...n-1),求出它的一个子矩阵b(i1...i2,j1...j2),使得b的所有元素和最大
 void MaxSum(int **a,int m,int n,int &besti1,int &besti2,int &bestj1,int &bestj2,int &sum)
 {
  int b;
  int i1,i2,j1,j2;
  int i,j;
  for(i2=m-1;i2>=0;i2--)
  {
   for(j2=n-1;j2>=0;j2--)
   {
    for(i1=0;i1<=i2;i1++)
    {
     for(j1=0;j1<=j2;j1++)
     {
      b=0;
      for(i=i1;i<=i2;i++)
      {
       for(j=j1;j<=j2;j++)
       {
        b+=a[i][j];
       }
      }
      if(b>sum)
      {
       sum=b;
       besti1=i1;
       besti2=i2;
       bestj1=j1;
       bestj2=j2;
      }
     }
    }
   }
  }
 }void main()
 {
  int m,n;
  cout<<"输入矩阵的行:";
  cin>>m;
  cout<<"输入矩阵的列:";
  cin>>n;
  int **a=new int*[n];
  int i,j;
  for(i=0;i<m;i++)
  {
   a[i]=new int[n];
  }
  for(i=0;i<m;i++)
  {
   cout<<"输入第"<<i<<"行数据:"<<endl;
   for(j=0;j<n;j++)
   {
    cin>>a[i][j];
   }
  }
  int i1,i2,j1,j2,sum=0;
  MaxSum(a,m,n,i1,i2,j1,j2,sum);
  cout<<"最大矩阵和的矩阵是:"<<endl;
  for(i=i1;i<=i2;i++)
  {
   for(j=j1;j<=j2;j++)
   {
    cout<<a[i][j]<<" ";
   }
   cout<<endl;
  }
  cout<<"最大矩阵和是:"<<sum<<endl;
 }