zoj 2659 Box

/*判断六个矩形能否组成长方体，我们只要找到一组充要条件去判断即可这里用的就是把边排序，然后根据对面必相等，相邻面有边重合判断 *///看了别人代码，再自己写出来的，无什么心情写这一题！囧！#include "iostream"#include "stdio.h"#include "algorithm"using namespace std;struct Rect{int x;int y;}rect[6];bool cmpy(Rect a, Rect b){if (a.x != b.x)return a.x < b.x;elsereturn a.y < b.y;}bool equal(Rect a, Rect b){return (a.x == b.x) && (a.y == b.y);}int main(){int i;while (1){bool flag = false;for (i = 0; i < 6; i++){            if( EOF == scanf("%d%d", &rect[i].x, &rect[i].y) ){                flag = true ;                break ;            }            if( rect[i].x > rect[i].y )                swap( rect[i].x, rect[i].y ) ;}if (flag)break; sort( rect, rect+6, cmpy );        if( !equal(rect[0],rect[1]) || !equal(rect[2],rect[3]) || !equal(rect[4],rect[5]) ||            rect[0].x!=rect[2].x || rect[0].y!=rect[4].x || rect[2].y!=rect[4].y )           cout << "IMPOSSIBLE" << endl;        else            cout << "POSSIBLE" << endl;}}