UVA-3.10-盒子-1587

#incl
4000
ude <stdio.h>
#include <stdlib.h>
#include <string.h>
struct A
{
int x;
int y;
};
int main()
{
struct A num[8];
//memset("num,0,sizeof(num)");
//freopen("D:\\output.txt", "w", stdout);
int a,b;
while(scanf("%d%d",&a,&b)!=EOF)
{
if(a>b)
{
num[1].y=a;
num[1].x=b;
}
else
{
num[1].x=a;
num[1].y=b;
}
int i,j,k,m,n;
n=6;
for(i=2; i<=6; i++)
{
scanf("%d%d",&a,&b);
if(a>b)
{
num[i].y=a;
num[i].x=b;
}
else
{
num[i].x=a;
num[i].y=b;
}
}
struct A t;
for(i=1; i<=n; i++)
{
for(j=1; j<=n-i; j++)
{
if(num[j].x>num[j+1].x)
{
t=num[j];
num[j]=num[j+1];
num[j+1]=t;
}
if(num[j].x==num[j+1].x)
{
if(num[j].y>num[j+1].y)
{
t=num[j];
num[j]=num[j+1];
num[j+1]=t;
}
}
}
}
int count=0;
struct A box[4];
//printf("11");
//printf("n=%d\n",n);
i=1;
for(i=1; i<=n; i++)
{
if(num[i].x==num[i+1].x&&num[i].y==num[i+1].y)
{
count=count+1;
box[count].x=num[i].x;
box[count].y=num[i].y;
//printf("**%d\n",count);
}
i++;
//printf("i=%d\n",i);
}
//printf("count=%d\n",count);
if(count!=3)
{
printf("IMPOSSIBLE\n");
continue;
}
//printf("\n");
else
{   //排序之后会符合下列规律
if(box[1].x!=box[2].x)
printf("IMPOSSIBLE\n");
else
if(box[1].y!=box[3].x)
printf("IMPOSSIBLE\n");
else
if(box[2].y!=box[3].y)
printf("IMPOSSIBLE\n");
else
printf("POSSIBLE\n");

}
}
return 0;
}