{"id":173,"date":"2010-03-20T21:50:00","date_gmt":"2010-03-20T13:50:00","guid":{"rendered":"http:\/\/localhost\/?p=173"},"modified":"2010-03-20T21:50:00","modified_gmt":"2010-03-20T13:50:00","slug":"hnoi2005_cunning_businessman","status":"publish","type":"post","link":"https:\/\/www.shuizilong.com\/wjmzbmr\/?p=173","title":{"rendered":"[HNOI2005]\u72e1\u733e\u7684\u5546\u4eba"},"content":{"rendered":"\n

[HNOI2005]\u72e1\u733e\u7684\u5546\u4eba<\/p>\n

Time Limit:10000MS  Memory Limit:165536K
Total Submit:44 Accepted:26
Case Time Limit:1000MS<\/p>\n

Description <\/strong><\/p>\n

\u5201\u59f9\u63a5\u5230\u4e00\u4e2a\u4efb\u52a1\uff0c\u4e3a\u7a0e\u52a1\u90e8\u95e8\u8c03\u67e5\u4e00\u4f4d\u5546\u4eba\u7684\u8d26\u672c\uff0c\u770b\u770b\u8d26\u672c\u662f\u4e0d\u662f\u4f2a\u9020\u7684\u3002\u8d26\u672c\u4e0a\u8bb0\u5f55\u4e86n\u4e2a\u6708\u4ee5\u6765\u7684\u6536\u5165\u60c5\u51b5\uff0c\u5176\u4e2d\u7b2ci \u4e2a\u6708\u7684\u6536\u5165\u989d\u4e3aAi(i=1,2,3…n-1,n)\uff0c \u3002\u5f53 Ai\u5927\u4e8e0\u65f6\u8868\u793a\u8fd9\u4e2a\u6708\u76c8\u5229Ai \u5143\uff0c\u5f53 Ai\u5c0f\u4e8e0\u65f6\u8868\u793a\u8fd9\u4e2a\u6708\u4e8f\u635fAi \u5143\u3002\u6240\u8c13\u4e00\u6bb5\u65f6\u95f4\u5185\u7684\u603b\u6536\u5165\uff0c\u5c31\u662f\u8fd9\u6bb5\u65f6\u95f4\u5185\u6bcf\u4e2a\u6708\u7684\u6536\u5165\u989d\u7684\u603b\u548c\u3002
\u5201\u59f9\u7684\u4efb\u52a1\u662f\u79d8\u5bc6\u8fdb\u884c\u7684\uff0c\u4e3a\u4e86\u8c03\u67e5\u5546\u4eba\u7684\u8d26\u672c\uff0c\u5979\u53ea\u597d\u8dd1\u5230\u5546\u4eba\u90a3\u91cc\u6253\u5de5\u3002\u5979\u8d81\u5546\u4eba\u4e0d\u5728\u65f6\u53bb\u5077\u770b\u8d26\u672c\uff0c\u53ef\u662f\u5979\u65e0\u6cd5\u5c06\u8d26\u672c\u5077\u51fa\u6765\uff0c\u6bcf\u6b21\u5077\u770b\u8d26\u672c\u65f6\u5979\u90fd \u53ea\u80fd\u770b\u67d0\u6bb5\u65f6\u95f4\u5185\u8d26\u672c\u4e0a\u8bb0\u5f55\u7684\u6536\u5165\u60c5\u51b5\uff0c\u5e76\u4e14\u5979\u53ea\u80fd\u8bb0\u4f4f\u8fd9\u6bb5\u65f6\u95f4\u5185\u7684\u603b\u6536\u5165\u3002
\u73b0\u5728\uff0c\u5201\u59f9\u603b\u5171\u5077\u770b\u4e86m\u6b21\u8d26\u672c\uff0c\u5f53\u7136\u4e5f\u5c31\u8bb0\u4f4f\u4e86m\u6bb5\u65f6\u95f4\u5185\u7684\u603b\u6536\u5165\uff0c\u4f60\u7684\u4efb\u52a1\u662f\u6839\u636e\u8bb0\u4f4f\u7684\u8fd9\u4e9b\u4fe1\u606f\u6765\u5224\u65ad\u8d26\u672c\u662f\u4e0d\u662f\u5047\u7684\u3002 <\/p>\n

Input <\/strong><\/p>\n

\u7b2c\u4e00\u884c\u4e3a\u4e00\u4e2a\u6b63\u6574\u6570w\uff0c\u5176\u4e2dw < 100\uff0c\u8868\u793a\u6709w\u7ec4\u6570\u636e\uff0c\u5373w\u4e2a\u8d26\u672c\uff0c\u9700\u8981\u4f60\u5224\u65ad\u3002\u6bcf\u7ec4\u6570\u636e\u7684\u7b2c\u4e00\u884c\u4e3a\u4e24\u4e2a\u6b63\u6574\u6570n\u548cm\uff0c\u5176\u4e2dn < 100\uff0cm < 1000\uff0c\u5206\u522b\u8868\u793a\u5bf9\u5e94\u7684\u8d26\u672c\u8bb0\u5f55\u4e86\u591a\u5c11\u4e2a\u6708\u7684\u6536\u5165\u60c5\u51b5\u4ee5\u53ca\u5077\u770b\u4e86\u591a\u5c11\u6b21\u8d26\u672c\u3002\u63a5\u4e0b\u6765\u7684m\u884c\u8868\u793a\u5201\u59f9\u5077\u770bm\u6b21\u8d26\u672c\u540e\u8bb0\u4f4f\u7684m\u6761\u4fe1\u606f\uff0c\u6bcf\u6761\u4fe1\u606f\u5360\u4e00\u884c\uff0c\u6709\u4e09 \u4e2a\u6574\u6570s\uff0ct\u548cv\uff0c\u8868\u793a\u4ece\u7b2cs\u4e2a\u6708\u5230\u7b2ct\u4e2a\u6708\uff08\u5305\u542b\u7b2ct\u4e2a\u6708\uff09\u7684\u603b\u6536\u5165\u4e3av\uff0c\u8fd9\u91cc\u5047\u8bbes\u603b\u662f\u5c0f\u4e8e\u7b49\u4e8et\u3002 <\/p>\n

Output <\/strong><\/p>\n

\u5305\u542bw\u884c,\u6bcf\u884c\u662ftrue\u6216false,\u5176\u4e2d\u7b2ci\u884c\u4e3atrue\u5f53\u4e14\u4ec5\u5f53\u7b2ci\u7ec4\u6570\u636e\uff0c\u5373\u7b2ci\u4e2a\u8d26\u672c\u4e0d\u662f\u5047\u7684\uff1b\u7b2ci\u884c\u4e3afalse\u5f53\u4e14\u4ec5\u5f53\u7b2ci\u7ec4\u6570\u636e\uff0c\u5373\u7b2ci \u4e2a\u8d26\u672c\u662f\u5047\u7684\u3002 <\/p>\n

Sample Input <\/strong><\/p>\n

2
3 3
1 2 10
1 3 -5
3 3 -15
5 3
1 5 100
3 5 50
1 2 51<\/p>\n

Sample Output <\/strong><\/p>\n

true
false<\/p>\n

Source <\/strong><\/p>\n

\u8fd9\u9053\u9898\u7684\u8bdddfs\u548c\u5e76\u67e5\u96c6\u90fd\u53ef\u4ee5\uff0cdfs\u662f\u9996\u5148dfs\u4e00\u4e0b\u628a\u6240\u6709\u7684\u503c\u63a8\u51fa\u6765\uff0c\u5728\u9047\u5230\u53cd\u5411\u8fb9\u7684\u65f6\u5019\u518d\u5224\u65ad\u4e00\u4e0b\u5c31\u53ef\u4ee5\u4e86\u3002\u4e0d\u8fc7\u8fd9\u6837\u8fd8\u8981\u6784\u56fe\uff0c\u8fd8\u662f\u76f4\u63a5\u5e76\u67e5\u96c6\u723d\uff0c
\u5e76\u67e5\u96c6\u5173\u952e\u5c31\u662f\u4fe1\u606f\uff0c\u4e3a\u6b64\u8003\u8651\u90e8\u5206\u548c\u5e8f\u5217\uff0c\u544a\u8bc9\u4f60s\u5230t\u7684\u548c\u5b9e\u9645\u4e0a\u5c31\u662fSum(t)-Sum(s-1)=v\u3002\u90a3\u4e48\u8fd9\u4e24\u4e2a\u7684\u4fe1\u606f\u5c31\u5173\u8054\u8d77\u6765\u4e86\uff0c\u90a3\u4e48\u5e76\u5728\u4e00\u8d77\u5e76\u4fdd\u5b58\u76f8\u5bf9\u4fe1\u606f\u5c31\u53ef\u4ee5\u4e86\u3002\u3002
Code:
#include<cstdio>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
const int maxn=100;
int n,m,F[maxn],G[maxn];
int Find(int x)
{
if(x==F[x])return x;
Find(F[x]);G[x]+=G[F[x]];return F[x]=F[F[x]];
}
void solve()
{
int s,t,v;
scanf("%d %d",&n,&m);
rep(i,n+1)F[i]=i,G[i]=0;
bool Right=1;
while(m–)
{
scanf("%d %d %d",&s,&t,&v);–s;
int i=Find(s),j=Find(t),a=G[s],b=G[t];
if(i!=j)
{
F[i]=j;
G[i]=b-a-v;
}
else if(b-a!=v)Right=false;
}
Right?puts("true"):puts("false");
}
int main()
{
int t;scanf("%d",&t);while(t–)solve();
} <\/p>\n","protected":false},"excerpt":{"rendered":"

[HNOI2005]\u72e1\u733e\u7684\u5546\u4eba Time Limit:10000MS  Memory Limit:165536KTotal Submit:44 Accepted:26 Case Time Limit:1000MS Description \u5201\u59f9\u63a5\u5230\u4e00\u4e2a\u4efb\u52a1\uff0c\u4e3a\u7a0e\u52a1\u90e8\u95e8\u8c03\u67e5\u4e00\u4f4d\u5546\u4eba\u7684\u8d26\u672c\uff0c\u770b\u770b\u8d26\u672c\u662f\u4e0d\u662f\u4f2a\u9020\u7684\u3002\u8d26\u672c\u4e0a\u8bb0\u5f55\u4e86n\u4e2a\u6708\u4ee5\u6765\u7684\u6536\u5165\u60c5\u51b5\uff0c\u5176\u4e2d\u7b2ci \u4e2a\u6708\u7684\u6536\u5165\u989d\u4e3aAi(i=1,2,3…n-1,n)\uff0c \u3002\u5f53 Ai\u5927\u4e8e0\u65f6\u8868\u793a\u8fd9\u4e2a\u6708\u76c8\u5229Ai \u5143\uff0c\u5f53 Ai\u5c0f\u4e8e0\u65f6\u8868\u793a\u8fd9\u4e2a\u6708\u4e8f\u635fAi \u5143\u3002\u6240\u8c13\u4e00\u6bb5\u65f6\u95f4\u5185\u7684\u603b\u6536\u5165\uff0c\u5c31\u662f\u8fd9\u6bb5\u65f6\u95f4\u5185\u6bcf\u4e2a\u6708\u7684\u6536\u5165\u989d\u7684\u603b\u548c\u3002 \u5201\u59f9\u7684\u4efb\u52a1\u662f\u79d8\u5bc6\u8fdb\u884c\u7684\uff0c\u4e3a\u4e86\u8c03\u67e5\u5546\u4eba\u7684\u8d26\u672c\uff0c\u5979\u53ea\u597d\u8dd1\u5230\u5546\u4eba\u90a3\u91cc\u6253\u5de5\u3002\u5979\u8d81\u5546\u4eba\u4e0d\u5728\u65f6\u53bb\u5077\u770b\u8d26\u672c\uff0c\u53ef\u662f\u5979\u65e0\u6cd5\u5c06\u8d26\u672c\u5077\u51fa\u6765\uff0c\u6bcf\u6b21\u5077\u770b\u8d26\u672c\u65f6\u5979\u90fd \u53ea\u80fd\u770b\u67d0\u6bb5\u65f6\u95f4\u5185\u8d26\u672c\u4e0a\u8bb0\u5f55\u7684\u6536\u5165\u60c5\u51b5\uff0c\u5e76\u4e14\u5979\u53ea\u80fd\u8bb0\u4f4f\u8fd9\u6bb5\u65f6\u95f4\u5185\u7684\u603b\u6536\u5165\u3002 \u73b0\u5728\uff0c\u5201\u59f9\u603b\u5171\u5077\u770b\u4e86m\u6b21\u8d26\u672c\uff0c\u5f53\u7136\u4e5f\u5c31\u8bb0\u4f4f\u4e86m\u6bb5\u65f6\u95f4\u5185\u7684\u603b\u6536\u5165\uff0c\u4f60\u7684\u4efb\u52a1\u662f\u6839\u636e\u8bb0\u4f4f\u7684\u8fd9\u4e9b\u4fe1\u606f\u6765\u5224\u65ad\u8d26\u672c\u662f\u4e0d\u662f\u5047\u7684\u3002 Input \u7b2c\u4e00\u884c\u4e3a\u4e00\u4e2a\u6b63\u6574\u6570w\uff0c\u5176\u4e2dw < 100\uff0c\u8868\u793a\u6709w\u7ec4\u6570\u636e\uff0c\u5373w\u4e2a\u8d26\u672c\uff0c\u9700\u8981\u4f60\u5224\u65ad\u3002\u6bcf\u7ec4\u6570\u636e\u7684\u7b2c\u4e00\u884c\u4e3a\u4e24\u4e2a\u6b63\u6574\u6570n\u548cm\uff0c\u5176\u4e2dn < 100\uff0cm < 1000\uff0c\u5206\u522b\u8868\u793a\u5bf9\u5e94\u7684\u8d26\u672c\u8bb0\u5f55\u4e86\u591a\u5c11\u4e2a\u6708\u7684\u6536\u5165\u60c5\u51b5\u4ee5\u53ca\u5077\u770b\u4e86\u591a\u5c11\u6b21\u8d26\u672c\u3002\u63a5\u4e0b\u6765\u7684m\u884c\u8868\u793a\u5201\u59f9\u5077\u770bm\u6b21\u8d26\u672c\u540e\u8bb0\u4f4f\u7684m\u6761\u4fe1\u606f\uff0c\u6bcf\u6761\u4fe1\u606f\u5360\u4e00\u884c\uff0c\u6709\u4e09 \u4e2a\u6574\u6570s\uff0ct\u548cv\uff0c\u8868\u793a\u4ece\u7b2cs\u4e2a\u6708\u5230\u7b2ct\u4e2a\u6708\uff08\u5305\u542b\u7b2ct\u4e2a\u6708\uff09\u7684\u603b\u6536\u5165\u4e3av\uff0c\u8fd9\u91cc\u5047\u8bbes\u603b\u662f\u5c0f\u4e8e\u7b49\u4e8et\u3002 Output \u5305\u542bw\u884c,\u6bcf\u884c\u662ftrue\u6216false,\u5176\u4e2d\u7b2ci\u884c\u4e3atrue\u5f53\u4e14\u4ec5\u5f53\u7b2ci\u7ec4\u6570\u636e\uff0c\u5373\u7b2ci\u4e2a\u8d26\u672c\u4e0d\u662f\u5047\u7684\uff1b\u7b2ci\u884c\u4e3afalse\u5f53\u4e14\u4ec5\u5f53\u7b2ci\u7ec4\u6570\u636e\uff0c\u5373\u7b2ci \u4e2a\u8d26\u672c\u662f\u5047\u7684\u3002 Sample Input 2 3 3 1 2 101 3 -53 3 -155 31 5 1003 5 501 2 51 Sample Output true […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/posts\/173"}],"collection":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=173"}],"version-history":[{"count":0,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=\/wp\/v2\/posts\/173\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=173"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=173"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shuizilong.com\/wjmzbmr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=173"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}