【BZOJ1997】[Hnoi2010]Planar【平面图判定】【2-SAT】

判断存在一条Hamilton回路的图是否是平面图。

和POJ3207几乎一样，只要把 判断相交的条件改成按回路编号比较就行了。

http://blog.youkuaiyun.com/braketbn/article/details/50834302

/* Footprints In The Blood Soaked Snow */
#include <cstdio>
#include <algorithm>

using namespace std;

const int maxm = 10005, maxn = maxm << 2, maxs = maxn, maxd = 205;

int n, m, head[maxn], cnt, dfn[maxn], low[maxn], clo, belong[maxn], tot, id[maxn];
bool ins[maxn];

struct _edge {
	int v, next;
} g[maxn];

struct _pos {
	int x, y;
} p[maxm];

inline int iread() {
	int f = 1, x = 0; char ch = getchar();
	for(; ch < '0' || ch > '9'; ch = getchar()) f = ch == '-' ? -1 : 1;
	for(; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
	return f * x;
}

inline int add(int u, int v) {
	g[cnt] = (_edge){v, head[u]};
	head[u] = cnt++;
}

int sta[maxs], top;

inline void tarjan(int x) {
	dfn[x] = low[x] = clo++;
	sta[++top] = x; ins[x]