#include "iostream.h"
//上三角矩陣壓縮存儲在一維數組中

//輸出上三角矩陣
void mprint(int b[],int n)
{int i,j,k;
for(i=0;i<n;i++)
{
	for(j=0;j<n;j++)
	if(i<=j)
		{		k=i*(2*n-i+1)/2+j-i;
	     cout<<b[k]<<"  ";}
	
	  else
	  { k=n*(n+1)/2;
		  if(b[k]!=0) cout<<b[k]<<"  ";
	      else cout<<"   ";
	  }
	
	  cout<<endl; 
}
cout<<endl; 
}
//上三角矩陣加法運算
void shangmatrixadd(int a[],int b[],int c[],int n)
{
int k=n*(n+1)/2;
for(int i=0;i<=k;i++) c[i]=a[i]+b[i];

}

//上三角矩陣減法運算
void shangmatrixsub(int a[],int b[],int c[],int n)
{
int k=n*(n+1)/2;
for(int i=0;i<=k;i++) c[i]=a[i]-b[i];

}
//上三角矩陣倍乘運算
void shangmatrixb(int a[],int p,int c[],int n)
{
int k=n*(n+1)/2;
for(int i=0;i<=k;i++) c[i]=p*a[i];

}

//上三角矩陣乘法運算
void shangmatrixmul(int a[],int b[],int c[],int n)
{
int m=n*(n+1)/2;
int i,j,k,v,p,q;
for(i=0;i<n;i++)
for(j=0;j<n;j++) 
{if(i<=j) v=i*(2*n-i+1)/2+j-i;
 else
	v=n*(n+1)/2;
 c[v]=0;
   for(k=0;k<n;k++)
   {if(i<=k) p=i*(2*n-i+1)/2+k-i;
    else p=n*(n+1)/2;
	if(k<=j)q=k*(2*n-k+1)/2+j-k;
    else q=n*(n+1)/2;
	   c[v]=c[v]+a[p]*b[q];
   }
}
}

void main()
{
	int a[]={1,2,4,3,5,7,0};
	int b[]={9,8,5,7,4,3,0};
	int c[20];
	mprint(a,3);
mprint(b,3);
//	shangmatrixadd(a,b,c,3);
//mprint(c,3);
//shangmatrixsub(a,b,c,3);
//mprint(c,3);
//shangmatrixb(a,4,c,3);
//mprint(c,3);
shangmatrixmul(a,b,c,3);
mprint(c,3);
}