不难想到是2-sat,这题最繁的就是加边的了
//#pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<iostream> #include<sstream> #include<cmath> #include<climits> #include<string> #include<map> #include<queue> #include<vector> #include<stack> #include<set> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int,int> pii; #define pb(a) push(a) #define INF 0x1f1f1f1f #define lson idx<<1,l,mid #define rson idx<<1|1,mid+1,r #define PI 3.1415926535898 template<class T> T min(const T& a,const T& b,const T& c) { return min(min(a,b),min(a,c)); } template<class T> T max(const T& a,const T& b,const T& c) { return max(max(a,b),max(a,c)); } void debug() { #ifdef ONLINE_JUDGE #else freopen("d:\in1.txt","r",stdin); freopen("d:\out1.txt","w",stdout); #endif } int getch() { int ch; while((ch=getchar())!=EOF) { if(ch!=' '&&ch!=' ')return ch; } return EOF; } const int maxn=100; struct twosat { int n; int mark[maxn*2]; vector<int> g[maxn*2]; int s[maxn],c; void init(int n) { this->n=n; memset(mark,0,sizeof(mark)); for(int i=0;i<2*n;i++) g[i].clear(); } bool dfs(int u) { if(mark[u^1])return false; if(mark[u])return true; mark[u]=1; s[c++]=u; for(int i=0;i<g[u].size();i++) { if(!dfs(g[u][i]))return false; } return true; } bool solve() { for(int i=0;i<2*n;i+=2) { if(!mark[i]&&!mark[i+1]) { c=0; if(!dfs(i)) { while(c)mark[s[--c]]=0; if(!dfs(i+1))return false; } } } return true; } void add_caluse(int x,int xval,int y,int yval) { x=x*2+xval; y=y*2+yval; g[x].push_back(y); // printf("%d->>%d ",x,y); } }; twosat solver; int dir(int x1,int y1,int x2,int y2) { int dx=x2-x1; int dy=y2-y1; if(dx<0||dy<0)return 0; else return 1; } void add(int n) { int a,b,x,y; scanf("%d%d%d%d",&a,&b,&x,&y); a--;b--;x--;y--; if(x!=a) { if(b!=y) solver.add_caluse(b+n,dir(x,b,a,b),a,dir(a,b,a,y)); solver.add_caluse(b+n,dir(x,b,a,b),y+n,dir(a,y,x,y)); if(b!=y) solver.add_caluse(y+n,dir(x,y,a,y),x,dir(x,b,x,y)); solver.add_caluse(y+n,dir(x,y,a,y),b+n,dir(a,b,x,b)); } if(b!=y) { if(a!=x) solver.add_caluse(a,dir(a,y,a,b),b+n,dir(a,b,x,b)); solver.add_caluse(a,dir(a,y,a,b),x,dir(x,b,x,y)); if(a!=x) solver.add_caluse(x,dir(x,y,x,b),y+n,dir(a,y,x,y)); solver.add_caluse(x,dir(x,y,x,b),a,dir(a,b,a,y)); } } int main() { //freopen("in.txt","r",stdin); int t; scanf("%d",&t); for(int ca=1;ca<=t;ca++) { int n,m,k; scanf("%d%d%d",&n,&m,&k); solver.init(n+m); for(int i=1;i<=k;i++) add(n); printf("%s ",solver.solve()?"Yes":"No"); } return 0; }