zoj3316 "General graph Max match with Flower tree Blossom"

Links: http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=3726

Algorithm See: http://fanhq666.blog.163.com/blog/static/8194342620120304463580/

Test instructions: There are n points on the board, and now two people take turns removing a child, each of which is removed from the last sub-Manhattan distance less than L. The last person who cannot be removed loses.

Analysis: points with a distance less than L are connected to the edge. If a connected block is not a complete match, the initiator must be able to go to a non-matching point, and then can not remove the child, if the next to remove the child, then there is a new match, now is a complete match.

Code:

#include <algorithm> #include <iostream> #include <cstring> #include <cstdio> #include < string> #include <vector> #include <queue> #include <cmath> #include <stack> #include <set > #include <map> #define INF 0x3f3f3f3f#define Mn 400#define Mm 200005#define mod 1000000007#define CLR (A, B) Memset ((a), (b), sizeof ((a))) #define CPY (a) memcpy ((a), (b), sizeof ((a))) #pragma comment (linker, "/stack : 102400000,102400000 ") #define UL u<<1#define ur (u<<1) |1using namespace Std;typedef long Long ll;struct edge {int v,next;} E[mm];struct point {int x, y;} P[mn];int Dis (point a,point b) {return abs (a.x-b.x) +abs (A.Y-B.Y);}    int tot,head[mn];void Addedge (int u,int v) {e[tot].v=v;    E[tot].next=head[u]; head[u]=tot++;} int pre[mn];int findpre (int x) {return x==pre[x]?pre[x]:p re[x]=findpre (pre[pre[x]]);}    void ol (int a,int b) {a=findpre (a);    B=findpre (b); if (a!=b) pre[a]=b;} int N,lk[mn],vis[mn],mark[mn],match[mn],ne[mn];int LCA(int x,int y)    {static int t=0;t++;            while (1) {if (x!=-1) {x=findpre (x);            if (vis[x]==t) return x;            vis[x]=t;            if (match[x]!=-1) x=ne[match[x]];        else X=-1;    } swap (x, y);        }}queue<int> q;void Group (int a,int p) {while (a!=p) {int b=match[a],c=ne[b];        if (Findpre (c)!=p) ne[c]=b;        if (mark[b]==2) Mark[b]=1,q.push (b);        if (mark[c]==2) Mark[c]=1,q.push (c);        OL (A, b), OL (B,C);    A=c;        }}void (int s) {for (int i=0;i<=n;i++) {ne[i]=-1;        Pre[i]=i;        mark[i]=0;    Vis[i]=-1;    } mark[s]=1;    while (!q.empty ()) Q.pop ();    Q.push (s);        while ((!q.empty ()) &&match[s]==-1) {int U=q.front ();        Q.pop ();            for (int i=head[u];~i;i=e[i].next) {int v=e[i].v; if (match[u]==v| | Findpre (U) ==findpre (v) | |            mark[v]==2) continue;                if (mark[v]==1) {int R=lca (U,V); if (Findpre (U)!=r) Ne[u]=v;                if (Findpre (v)!=r) Ne[v]=u;                Group (U,R);            Group (V,R);                } else if (match[v]==-1) {ne[v]=u; for (int x=v;~x;)                    {int y=ne[x];                    int mv=match[y];                    Match[x]=y,match[y]=x;                X=MV;            } break;                } else {ne[v]=u;                Q.push (Match[v]);                Mark[match[v]]=1;            mark[v]=2;    }}}}void init () {tot=0; CLR (head,-1);}        int main () {while (~SCANF ("%d", &n)) {int l;init ();        for (int i=1;i<=n;i++) scanf ("%d%d", &p[i].x,&p[i].y);        scanf ("%d", &l);                    for (int i=1;i<n;i++) {for (int j=i+1;j<=n;j++) {if (DIS (p[i],p[j]) <=l) {                    Addedge (I,J);                Addedge (J,i); }}} for (int i=1;i<=n;i++) Match[i]=-1;        for (int i=1;i<=n;i++) {if (match[i]==-1) (i);        } int ans=0;        for (int i=1;i<=n;i++) {if (match[i]!=-1) ans++;        } if (ans==n) {printf ("yes\n");    } else printf ("no\n"); } return 0;}

zoj3316 "General graph Max match with Flower tree Blossom"