摘要：
思路：二分枚举建边，用DLX判断是否满足。#include#include#include#include#include#include#include#include#include#include#define clr(x,y) memset(x,y,sizeof(x))#define pb push_back#define mp make_pair#define Maxn 20010#define LL __int64#define Abs(x) ((x)>0?(x):(-x))#define lson(x) (x m) return false; if (R[0] == 0) 阅读全文