这是在干什么？
for i:=1 to n do
if (not f[i]) or (s=n-1) then
begin
g:=true;
for j:=1 to s-1 do
if (s<>n-1) or (j<>1) then if not a[w[s],i,w[j-1],w[j]] then g:=false;
if g then
begin
f[i]:=true;
w[s+1]:=i;
search(s+1);
f[i]:=false;
end;
end;
//我的程序如下，就是从每个点出发深搜，同时满足和前面的线不相交，最后把结果除2，但是一个点都不过，请帮忙查找错误。或者发C/C++的AC程序也行
#include <stdio.h>
#include <string.h>
struct point { int x, y; };
int min(int a, int b) { return a < b ? a : b; }
int max(int a, int b) { return a > b ? a : b; }
bool inter(point a, point b, point c, point d){
if ( min(a.x, b.x) > max(c.x, d.x) ||
min(a.y, b.y) > max(c.y, d.y) ||
min(c.x, d.x) > max(a.x, b.x) ||
min(c.y, d.y) > max(a.y, b.y) ) return 0;
int h, i, j, k;
h = (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
i = (b.x - a.x) * (d.y - a.y) - (b.y - a.y) * (d.x - a.x);
j = (d.x - c.x) * (a.y - c.y) - (d.y - c.y) * (a.x - c.x);
k = (d.x - c.x) * (b.y - c.y) - (d.y - c.y) * (b.x - c.x);
return h * i <0 && j * k <0;
}
point A[11];
int n;
int line[50][2];
int XX[50][50];
int pp[10][10];
char d[10];
char v[10];
int ans;
void dfs(int from , int deep)
{
int i,j,k,s;
v[from]=1;
d[deep]=from;
for(i=0;i<n;i++)
{
if(!v[i])
{
k=pp[from][i];
for(j=0;j<deep;j++)
{
s=pp[d[j]][d[j+1]];
if(XX[k][s]) break;
}
if(j==deep)
dfs(i,deep+1);
}
}
if(deep==n-1)
ans++;
v[from]=0;
}
int main()
{
int i,j,k=0;
while(1)
{
scanf("%d%d",&A[n].x,&A[n].y);
if(!A[n].x&&!A[n].y) break;
n++;
}
for(i=0;i<n;i++)
{
for(j=i+1;j<n;j++)
{
line[k][0]=i;
line[k][1]=j;
pp[i][j]=pp[j][i]=k;
k++;
}
}
for(i=0;i<k;i++)
{
for(j=i+1;j<k;j++)
{
if((line[i][0]==line[j][0])||(line[i][0]==line[j][1])||(line[i][1]==line[j][0])||(line[i][1]==line[j][1])) continue;
if(inter(A[line[i][0]], A[line[i][1]], A[line[j][0]], A[line[j][1]]))
XX[i][j]=XX[j][i]=1;
}
}
for(i=0;i<n;i++)
{
dfs(i,0);
}
printf("%d",ans/2);
return 0;
}