#include<stdio.h>
#include<stdlib.h>
#include<math.h>
void  sanjiaoxing()
{
    int x1,y1,x2,y2,x3,y3;
    double  area,s;
    double g,h,i;
    printf("请输入3个点的坐标，(不用加括号，坐标之间用逗号隔开)");
    scanf("%d,%d%d,%d%d,%d",&x1,&y1,&x2,&y2,&x3,&y3);
+     g=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
     h=sqrt((x2-x3)*(x2-x3)+(y2-y3)*(y2-y3));
     i=sqrt((x3-x1)*(x3-x1)+(y3-y1)*(y3-y1));
         if(g>=h+i||h>=g+i||i>=g+h)
     {
         printf("不是三角形");
     }
         else if(g=h=i)
         {
             printf("等边三角形");
         }
         else if(g*g==i*i+h*h||i*i==g*g+h*h||h*h==i*i+g*g)
         {
             printf("直角三角形");
         }
         else printf("一般三角形");
      s=(g+h+i)/2.0;
      area=sqrt(s*(s-g)*(s-h)*(s-i));
      printf("三角形的面积为：%f\n",area);
}

void main()                                        //程序主函数...
{
  printf("\n\n\n\n\n\t\t    ~********欢迎进入经典算法系统********~\n\n\n\n");   //欢迎界面...
  printf("\t\t~***********制作者：***  2013年6月***********~\n\n\n\n");
  printf("\t\t    ~**********按任意键进入主菜单：**********~");
  getchar();
  menu();
}

menu()
{
    char c;

do
   {
     system("cls");
     printf("\n\n\t\t      ~*****************************~\n");    //主菜单...
     printf("\n\t\t                  主 菜 单\n");  
     printf("\n\t\t      ~*****************************~\n\n\n");
     printf("\n>***********判断三角形**************<\n");
     printf("\t\t0:退出系统\n");
     do{
         printf("\n\t   请选择输入选项【1\\0】:_");
         c=getchar();getchar();                             //读取输入数字...
     }while(c!='1'&&c!='0');
     
     switch(c)                                          //判断所选项目...
       {
         case '1': sanjiaoxing();break;
         case '0': system("cls");exit(0);
       }
     printf("\n按任意键返回主菜单:_");
     getchar();                                      //读取选择的任意键...                     
     system("cls");
   }while(1);

}