找出最長的順序子序列

這幾個月到了新公司，忙活了一段時間。

好久沒有玩online judge了，今天去做了一道。腦子有點廢掉了。

 

題目在這裏 Link 要找出一個序列中最長的子序列的長度，有點像迷宮探索的那種思路。

走出一條路徑，然後退一步，看看有沒有別的路徑，都走完了再退一步。就這個思路。

 

 

import sys; def findNext(startIndex,currentBase,list): while startIndex<=len(list)-1: if(list[startIndex]>currentBase): return startIndex; else: startIndex=startIndex+1; return None; def CalculateMaxSubsquence(list): startIndex=0; FirstNodeIndex=0; subSequence=[]; subIndexList=[]; currentBase=0; max=0; while FirstNodeIndex<len(list)-1: next=findNext(startIndex,currentBase,list); if next!=None: subSequence.append(list[next]); subIndexList.append(next); currentBase=list[next]; startIndex=next+1; else: #print subSequence; if max<len(subSequence): max=len(subSequence); count=len(subSequence); removeIndex=subIndexList[count-1]; subIndexList.remove(removeIndex); subSequence.remove(list[removeIndex]); if removeIndex==len(list)-1:#if meet the end of the list, remove 2 removeIndex=subIndexList[count-2]; subIndexList.remove(removeIndex); subSequence.remove(list[removeIndex]); if len(subSequence)!=0:#adjust the following node startIndex=removeIndex+1; currentBase=subSequence[len(subSequence)-1]; else:#move the first node forward FirstNodeIndex=FirstNodeIndex+1; subIndexList.append(FirstNodeIndex); subSequence.append(list[FirstNodeIndex]); currentBase=list[FirstNodeIndex]; startIndex=FirstNodeIndex+1; return max; inputcount=str(sys.stdin.readline()); result=[]; for i in range(int(inputcount)): blank=str(sys.stdin.readline()); numberCount=str(sys.stdin.readline()); inputList = str(sys.stdin.readline()); dataList=[]; for data in inputList: if data!=' 'and data!='/n' and data!='/r': dataList.append(data); #dataList=[1, 7, 3, 5, 9, 4, 8]; result.append(CalculateMaxSubsquence(dataList)); for s in result: print '/r'; print s;