比较混乱 就是枚举，那位给我看下或者给个正确的代码

#include <iostream>
#include <iomanip>
#include <cmath>
#include <string>
using namespace std;

#define DMAX 10e30;


struct CPoint
{
   double x, y;
}  ;

CPoint up[20], dp[20];

int n;
double ans;
bool same(double d1, double d2)
{
	 return fabs(d1 - d2) < 0.000000001;
}
int length(CPoint& p1, CPoint& p2, int lim)
{
	int k;
	double s, s1;
	double d, d1;
	double x, y, xx;
	s = (p2.y - p1.y)/(p2.x - p1.x);
	d = p1.y - s*p1.x;
	for(k = 0; k < n; k ++)
	{
		y = s*up[k].x + d;
		if(!same(y, dp[k].y) && !same(y, up[k].y))
			if(y < up[k].y - 1 || y > up[k].y)
			         break;
	}
	if(k == n)
		return -1;
	if(k <= lim)
		return 0;
	if(k)
	{ 
		//直线方程 y = s1*x + d1 和 y = s*x + d的交点
		s1 = (up[k].y - up[k - 1].y)/(up[k].x - up[k - 1].x);
		d1 =  up[k - 1].y - s1*up[k - 1].x;
		x = (d - d1)/(s1 - s);	
		xx = - DMAX;
		if((x > up[k - 1].x && x < up[k].x) || same(x, up[k - 1].x)
			|| same(x, up[k].x))
		    xx = max(x, xx);
		d1 --; //管道的下边界
		x = (d - d1)/(s1 - s);
	    if((x > up[k - 1].x && x < up[k].x) || same(x, up[k - 1].x)
			|| same(x, up[k].x))
		      xx = max(x, xx);
		ans = max(xx, ans);
	}
	return 0;
}

void solve()
{
	int i, j;
	int sig;
	for(i = 0; i < n; i ++)
	  for(j = i + 1; j < n; j ++)
	  {	
		  {
		  sig = length(up[i], dp[j], j);
		  if(sig == -1)
		  {
			  cout << "Through all the pipe.\n";
			  return;
		  }
		  sig = length(dp[i], up[j], j);
		  if(sig == -1)
		  {
			  cout << "Through all the pipe.\n";
			  return;
		  }
		  }
	 }
 	 cout << fixed << setprecision(2) << ans << endl;
}

int  main()
{ 

	int i;
	ans = - DMAX;
	while(cin >> n && n)
	{
		for(i = 0; i < n; i ++)
		{
			cin >> up[i].x >> up[i].y;
			dp[i].x = up[i].x;
			dp[i].y = up[i].y - 1;
		}
	    solve();
	}
	return 0;   
}




	




		

• Re:老wa， 找不出问题 代码如下 (53) first 2006-05-24 13:39:02
• Re:老wa， 找不出问题 代码如下 (2136) newjunwei 2008-05-04 10:11:40