{"id":431,"date":"2009-03-28T20:07:35","date_gmt":"2009-03-28T12:07:35","guid":{"rendered":"http:\/\/sinyalee.com\/blog\/?p=431"},"modified":"2009-03-28T20:07:35","modified_gmt":"2009-03-28T12:07:35","slug":"apio-2008-%e5%85%8d%e8%b4%b9%e9%81%93%e8%b7%af%ef%bc%88roads%ef%bc%89-%e8%a7%a3%e9%a2%98%e6%8a%a5%e5%91%8a","status":"publish","type":"post","link":"https:\/\/sinyalee.com\/blog\/?p=431","title":{"rendered":"APIO 2008 \u514d\u8d39\u9053\u8def\uff08roads\uff09 \u89e3\u9898\u62a5\u544a"},"content":{"rendered":"

\u9898\u76ee\u4e0e\u6570\u636e\u79fb\u6b65APIO\u5b98\u65b9\u7f51\u7ad9\uff1ahttp:\/\/www.apio.olympiad.org\/<\/a> <\/p>\n

\u9996\u5148\u6211\u4eec\u770b\u5230\u8fd9\u9053\u9898\uff0c\u4fbf\u6709\u4e00\u4e2a\u5de8\u5927\u7684\u53d1\u73b0\uff01 <\/p>\n

\u6309\u7167\u6d01\u7656<\/font>\u52c7\u54e5\u6240\u8bf4\u7684\u5c31\u662f\uff1a\u9e45\u5375\u77f3\u8def\u548c\u6c34\u6ce5\u8def\u662f\u540c\u7b49\u5730\u4f4d\u7684\uff01\u8981\u62ffk\u4e2a\u9e45\u5375\u77f3\u8def\u6765\u751f\u62101\u68f5\u6811\uff0c\u4fbf\u662f\u8981\u62ffn-1-k\u4e2a\u6c34\u6ce5\u8def\u6765\u751f\u6210\u4e00\u68f5\u6811\u3002 <\/p>\n

\u8fd9\u4e2a\u53d1\u73b0\u6709\u4ec0\u4e48\u7528\u5462\uff1f <\/p>\n

== <\/p>\n

== <\/p>\n

== <\/p>\n

== <\/p>\n

\u57fa\u672c\u6ca1\u7528 = =||| <\/p>\n

\u6709\u65f6\u5019\u505a\u6570\u5b66\u9898\uff0c\u540c\u7b49\u5730\u4f4d\u7684\u4e1c\u897f\u8fd8\u8981\u7528\u4e00\u4e2a\u4ec0\u4e48\u201c\u4e3b\u5143\u6cd5\u201d\u4e4b\u7c7b\u7684\u4e1c\u897f\uff0c\u8fd8\u6709\u4ec0\u4e48\u504f\u5bfc\u6570\u2026\u2026\u6211\u7684\u89e3\u6cd5\u662f\u8981\u8ba9\u5b83\u5730\u4f4d\u4e0d\u5747\u7b49\u7684\uff0c\u4e0d\u59a8\u5c31\u6309\u7167\u53d6k\u4e2a\u9e45\u5375\u77f3\u8def\u7684\u601d\u8def\u6765\u505a\u3002 <\/p>\n

\u9996\u5148\u6211\u4eec\u53d1\u73b0\u6709\u4e00\u4e9b\u9e45\u5375\u77f3\u8def\u65f6\u5fc5\u987b\u8981\u7ef4\u62a4\u7684\u3002\u5c31\u662f\u67d0\u4e9b\u533a\u5757\u4e0d\u8d70\u9e45\u5375\u77f3\u8def\u65e0\u6cd5\u901a\u8fc7\u3002\u5c31\u662f\u5148\u5047\u8bbe\u6240\u6709\u6c34\u6ce5\u8def\u90fd\u7ef4\u62a4\uff0c\u7136\u540e\u4fbf\u8fde\u6210\u4e00\u4e9b\u4e0d\u76f8\u4ea4\u96c6\uff08\u5e76\u67e5\u96c6\uff09\u3002\u8fd9\u4e9b\u96c6\u4e4b\u95f4\u5c31\u8981\u5fc5\u5b9a\u8981\u7528\u5230\u9e45\u5375\u77f3\u8def\u6765\u8fde\u63a5\u3002\u8fd9\u4e9b\u9e45\u5375\u77f3\u8def\u5c31\u5fc5\u987b\u8981\u7ef4\u62a4\u3002\u5982\u679c\u5fc5\u8981\u7684\u9e45\u5375\u77f3\u8def\u8d85\u8fc7k\uff0c\u90a3\u4e48\u5c31\u65e0\u89e3\uff0c\u5426\u5219\u80af\u5b9a\u6709\u89e3\u3002 <\/p>\n

\u7136\u540e\u6e05\u7a7a\u4e0d\u76f8\u4ea4\u96c6\u3002\u518d\u7528\u5fc5\u987b\u7ef4\u62a4\u7684\u9e45\u5375\u77f3\u8def\u53bb\u66f4\u65b0\u4e0d\u76f8\u4ea4\u96c6\uff0c\u5982\u679c\u9e45\u5375\u77f3\u8def\u4e0d\u8db3k\uff0c\u90a3\u4e48\u5269\u4e0b\u7684\u9e45\u5375\u77f3\u8def\u4efb\u53d6\uff08\u53ea\u8981\u4e0d\u5f62\u6210\u73af\uff09\u3002\u7136\u540e\u518d\u53d6n-1-k\u4e2a\u77f3\u5b50\u8def\uff0c\u53ea\u8981\u4e0d\u5f62\u6210\u73af\u5c31\u53ef\u3002 <\/p>\n

\u6211\u7684\u7a0b\u5e8f\uff1a <\/p>\n

\/*
ID: sinya1
PROG: roads
LANG: C++
*\/ <\/p>\n

#include <iostream> <\/p>\n

#define maxn 200001
#define maxm 1000000 <\/p>\n

using namespace std; <\/p>\n

int n,m,k,cobh=0,conh=0,solh=0;
int cob1[maxm],cob2[maxm],con1[maxm],con2[maxm];
int sol1[maxn],sol2[maxn],sol3[maxn];
int r[maxn]; <\/p>\n

void init() { 
  scanf(“%d%d%d”,&n,&m,&k);
  int a,b,c;
  for (int i=0;i<m;i++) {
    scanf(“%d%d%d”,&a,&b,&c);
    if (c) {
      con1[conh]=a;
      con2[conh++]=b;
    }
    else {
      cob1[cobh]=a;
      cob2[cobh++]=b;
    }
  }
} <\/p>\n

int get(const int x) {
  if (r[x]<0) return x;
  return r[x]=get(r[x]);
} <\/p>\n

void un(int x,int y) {
  x=get(x);y=get(y);
  if (x==y) return;
  if (r[x]<r[y]) r[y]=x;
  else {
    if (r[y]<r[x]) r[x]=y;
    else {
      r[x]=y;
      r[y]–;
    }
  }
} <\/p>\n

bool work() {
  memset(r,255,sizeof(r));
  for (int i=0;i<conh;i++) un(con1[i],con2[i]);
  for (int i=0;solh<k&&i<cobh;i++)
    if (get(cob1[i])!=get(cob2[i])) {
      un(cob1[i],cob2[i]);
      sol1[solh]=cob1[i];
      sol2[solh]=cob2[i];
      sol3[solh++]=0;
    }
  memset(r,255,sizeof(r));
  for (int i=0;i<solh;i++) un(sol1[i],sol2[i]);
  for (int i=0;i<cobh && solh<k;i++)
    if (get(cob1[i])!=get(cob2[i])) {
      un(cob1[i],cob2[i]);
      sol1[solh]=cob1[i];
      sol2[solh]=cob2[i];
      sol3[solh++]=0;
    }
  if (solh<k) return 0;
  for (int i=0;i<conh;i++)
    if (get(con1[i])!=get(con2[i])) {
      un(con1[i],con2[i]);
      sol1[solh]=con1[i];
      sol2[solh]=con2[i];
      sol3[solh++]=1;
    }
  if (solh<n-1) return 0;
  else return 1;
} <\/p>\n

void output() {
  for (int i=0;i<n-1;i++)
    printf(“%d %d %d\\n”,sol1[i],sol2[i],sol3[i]);
} <\/p>\n

int main() { 
  freopen(“roads.in”,”r”,stdin);
  freopen(“roads.sol”,”w”,stdout); <\/p>\n

  init();
  if (work()) output();
  else printf(“no solution\\n”);
  return 0;
}<\/p>\n","protected":false},"excerpt":{"rendered":"

\u9898\u76ee\u4e0e\u6570\u636e\u79fb\u6b65APIO\u5b98\u65b9\u7f51\u7ad9\uff1ahttp:\/\/www.apio.olympiad.org\/ \u9996\u5148\u6211\u4eec\u770b\u5230\u8fd9\u9053\u9898 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[23,131,344],"class_list":["post-431","post","type-post","status-publish","format-standard","hentry","category-13","tag-apio","tag-131","tag-344"],"_links":{"self":[{"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/431","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=431"}],"version-history":[{"count":0,"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/431\/revisions"}],"wp:attachment":[{"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=431"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=431"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sinyalee.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}