#include<iostream>#include <iomanip>using namespace std;enum TriangleTye{leftBottom,leftUp,rightBottom,rightUp};struct TriangleMatrix{    int* nums;    int scale;    TriangleTye triangleTye;    int size;};TriangleMatrix* createTriangleMatrix(int scale,TriangleTye triangleTye){    int size = scale*(scale+1)/2;    TriangleMatrix* p = (TriangleMatrix*)malloc(sizeof(TriangleMatrix));    p->nums = new int[size+1];    p->scale=scale;    p->triangleTye=triangleTye;    p->size=size;    return p;}int getElement(TriangleMatrix* matrix,int i,int j){    switch ((matrix->triangleTye))    {    case leftBottom:        if(i<j)            return 0;        else return matrix->nums[i*(i-1)/2+j-1];        break;    case leftUp:        if(matrix->scale-i+1<j)            return 0;        else return matrix->nums[matrix->size - ((matrix->scale-i)*(matrix->scale-i+1)/2+(matrix->scale-i+1-j))-1];        break;    case rightBottom:        if(matrix->scale-i+1>j)            return 0;        else return matrix->nums[i*(i-1)/2+j-(matrix->scale-i)-1];        break;    case rightUp:        if(i>j)            return 0;        else  return matrix->nums[matrix->size - (matrix->scale-i+1)*(matrix->scale-i+2)/2+j-i];        break;    default:        return -1;        break;    }}void OuptPut(TriangleMatrix* p){        for(int i=1;i<=p->scale;i++)    {        for(int j=1;j<=p->scale;j++)        {            printf("%d ",getElement(p,i,j));         }        printf("\n");     }}void main(){    printf("\n");     printf("%s","four kinds of triangle matrix, and the elements is:");     printf("\n");     int x=9;    TriangleMatrix* p= createTriangleMatrix(x,leftBottom);    for(int i=0;i<x*(x+1)/2;i++)    {        p->nums[i]=rand()%10;        printf("%d ",p->nums[i]);     }     printf("\n");      printf("vertical corner at leftBottom:\n");      OuptPut(p);     printf("vertical corner at rightBottom:\n");      p->triangleTye = rightBottom;     OuptPut(p);     printf("vertical corner at leftUp:\n");      p->triangleTye = leftUp;     OuptPut(p);    printf("vertical corner at rightUp:\n");      p->triangleTye = rightUp;     OuptPut(p);    printf("Done\n");     scanf("%d",&x);}