POJ 1788

求多边形周长。角都是直角。

 

View Code

 1 #include <iostream>

 2 #include <cstring>

 3 #include <cstdio>

 4 #include <cstdlib>

 5 #include <algorithm>

 6 

 7 #define N 222222

 8 

 9 using namespace std;

10 

11 struct PO

12 {

13     int x,y;

14 }p[N];

15 

16 int n;

17 

18 inline bool cmpx(const PO &a,const PO &b)

19 {

20     if(a.x==b.x) return a.y<b.y;

21     return a.x<b.x;

22 }

23 

24 inline bool cmpy(const PO &a,const PO &b)

25 {

26     if(a.y==b.y) return a.x<b.x;

27     return a.y<b.y;

28 }

29 

30 inline void read()

31 {

32     for(int i=1;i<=n;i++) scanf("%d%d",&p[i].x,&p[i].y);

33 }

34 

35 inline void go()

36 {

37     int ans=0;

38     sort(p+1,p+1+n,cmpx);

39     for(int i=1;i<=n;i+=2) ans+=p[i+1].y-p[i].y;

40     sort(p+1,p+1+n,cmpy);

41     for(int i=1;i<=n;i+=2) ans+=p[i+1].x-p[i].x;

42     printf("The length of the fence will be %d units.\n",ans);

43 }

44 

45 int main()

46 {

47     while(scanf("%d",&n),n) read(),go();

48     return 0;

49 }