Football Games Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 802    Accepted Submission(s): 309 Problem Description A mysterious country will hold a football world championships---Abnormal Cup…

http://acm.hdu.edu.cn/showproblem.php?pid=5873 题意: 现在有比赛,所有队伍两两进行比赛,赢的积2分,输的积0分,如果平局的话就各自都积1分,现在给出每只队伍的得分情况,判断是否合法. 思路: 竞赛图中有关于得分序列这方面的知识,这里引用一下来自http://blog.csdn.net/a_crazy_czy/article/details/73611366博主的讲解. 那么,对于这道题目来说,首先对所有得分排个序,再依次处理即可,前i只队伍的得分情…

随便判了几个条件就过了,也不知道对不对的. 正解应该是: $[1].$${s_1} + {s_2} + {s_3} + ...... + {s_n} = n(n - 1)$ $[2].$${s_1} + {s_2} + {s_3} + ...... + {s_i} ≥ i(i - 1)$ #pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring&g…

题目 本题需要用到的结论: 一.兰道定理 二.如果\(n\geq4\),那么\(n\)个点的强连通竞赛图存在\(n-1\)个点的强连通子图. 证明: 现在有一个n-1个点的竞赛图(不一定强连通,称其为原图),加入n号点,得到的n个点的竞赛图是强连通的.将原图强连通分量分解,按照拓扑序排好,称为\(a_0 \cdots a_k\)(一共k个强连通分量).现在考虑证明加入n号点后的图,删掉某一个点后一定可以得到强连通图. k=1:去掉n号点即可. \(k \geq 3\):原图是长成这样的(不太准确…

兰道定理的内容: 一个竞赛图强连通的充要条件是:把它的所有顶点按照入度d从小到大排序,对于任意\(k\in [0,n-1]\)都不满足\(\sum_{i=0}^k d_i=\binom{k+1}{2}\). 兰道定理的证明: 引理: 一个竞赛图强连通的充要条件是对于任意\(S \subsetneq 点集V\),都存在一个点\(u \notin S\),满足u到S有边. 证明: 1.必要性:比较显然 2.充分性:假设我们现在已经得到了\(V\)中的一个强连通子集\(S\),想办法不断扩展\(S\)…

Football Games Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 439    Accepted Submission(s): 157 Problem Description A mysterious country will hold a football world championships---Abnormal Cup…

题目链接:http://acm.hdu.edu.cn/contests/contest_showproblem.php?cid=725&pid=1006 Football Games Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 3505    Accepted Submission(s): 655 Problem Descriptio…

题目链接: Football Games 分析: 先将分数排序,然后 设当前队编号为p,设个指针为p+1,然后p>1,每次p-=2,指针右移一位p==1,指针指向的队-=1p==0,从指针开始到n,都减去2如果出现一个数小于0,判错,如果最后一个数非0,盘错其他判对 (如有反例请指正) 代码: #include <cstdio> #include <cstring> #include <cstdlib> #include <ctime> #includ…

Football Games Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description A mysterious country will hold a football world championships---Abnormal Cup, attracting football teams and fans from all around th…

Football Games Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 5055    Accepted Submission(s): 904 Problem Description A mysterious country will hold a football world championships---Abnormal Cu…