集训队作业解题报告

1、Ural1569Networkingthe优先考虑满足条件X 在规定当条件X不成立，Di=2di；当条件X 成立，Ural1569Networkingthe优先考虑满足条件X 在规定当条件X不成立，Di=2di；当条件X 成立，Di=2di -1取出使得DiViBFSTi。 C，设AB 上距离C 最近的点位Q，不妨Q 在AP 上，则CP=BC-BPAB-Q，不妨Q在AP CP=BC-BPAB-R 在 。同时D 2 TP ) 的直径。所以 T的直径都不超过T 的直径，即 T一定是该图的一棵直径最小生成树。BQ意C则 CQ的子孙。那么，T”是符合X条件的。另一方面，对于任意一棵符合XP 为根BFS

2、 2l(P)-1=DPT0，设所有满PC=l(P)的点 C，都Q0 的子孙。那么显然 T0 的直 用Floyd 算法与处理所有两点间的距离。总算法复杂度是O(n3)D2constvara:array1.maxn,1.maxnof;fori:=1tonnfijthenfor j:=1 fori:=1todobeginreadln(j,k);aj,k:=1;ak,j:=1;for k:=1tonn fori:=1 constvara:array1.maxn,1.maxnof;fori:=1tonnfijthenfor j:=1 fori:=1todobeginreadln(j,k);aj,k:=1

3、;ak,j:=1;for k:=1tonn fori:=1 forj:=1 tonifai,k+ak,jdisthenai,j=1thenfork:=1 nfai,k=disifaj,kdis-1thenbeginflag:=false;break;end; if flag then break;ifflagthendis:=dis*2-1elsehenbeginans:=i;min:=dis;ifflagthenod2=0fans:=trueelsefori:=1tomindo for j:=1 to nfaans,j=ithennfaans,k=i-1fork:=1 ifaj,k=1the

4、niffkthenbeginflag:=false;break;ifnotflagthenbeginfj:=true;n(j,k);continue;for k:=1 tofaans,k=i-1ifaj,k=1thenbeginn(j,k);break;1569. Networking TimeLimit:1.0second Memory Limit: 64 MBTheresnotmuchtimeleftuntilthe“Iset”toweropensforbutacomputernetworkisnotyethebuilding.Theisexpectedto1569. Networking

5、 TimeLimit:1.0second Memory Limit: 64 MBTheresnotmuchtimeleftuntilthe“Iset”toweropensforbutacomputernetworkisnotyethebuilding.Theisexpectedtobeveryrobustandshouldhavelotsofbranches.ThereNhetshouldbeconnectedwiththisnetwork.These beconnectedwithMdirectlinks,withnomore n n each pair of nodes. To save

6、some time, it wasnodeswereplannedto one direct link bet tarerequiredtomakeaconnectedwillbeinstalled;alltheremainingwiresaregoingtobelaidafterthe openingceremony.Inordertobeefficientnetworkshouldhaveonemorerequirement:aldistancenitsnodesmustassmallible.DistancenapairofnodesAandBisasthenumberof node B

7、.ermediatenodesonthepathfromthenodeAtoegersN(2N100)andM(1Mlinecontains10000).ThefollowingMlinesdescribetheinitialplannednetworkEachoftheselinescontainsapairegersnumbersoftdirectlink.Nodesarenumberedfrom1toN.This guaranteed to be connected, and there are no links with itself.are connected wi networklayoutis connecting a The new network layout he same S4 1 2 2 3 1 2 2 P