#include<iostream>
using namespace std;
int main{
int middle = 0;int up = 0;int low = 0;
int a2d[4][4]={
{1,2,3,4},
{5,6,7,8},
{8,7,6,5},
{4,3,2,1}}
int(*p2d)[4]=a2d;
for(int a = 0;a<=3;a++){
middle += *(*(p2d+a)+a);}
cout<<"主对角线的和为:"<<middle<<endl;
for(int n=3;n>=0;n--){
for(int b = 0;n-b>=0;b++){
low += *(*(p2d+n)+(n-b))}
}
cout<<"下三角形的和为:"<<low<<endl;
for(int m=0;m<=3;m++){
for(int c=0;c+m<=3;c++){
up += *(*(p2d+m)+(c+m))}
}
cout<<"上三角形的和为:"<<up<<endl;
return 0;
}