google code jam exercise——Rope Intranet

Round 1C 2010，C輪的測試題了。本以為難度會加大，不過第一題還是比較簡單的。

Rope Intranet，統計繩子的交點個數。演算法很直接，遍曆所有的繩子，累計它與剩下的繩子的交點的個數。

代碼如下：

#!/usr/bin/python#encoding:UTF-8#Filename:RopeIntranet.pyimport sysdef compareWire(a,b):    if (a[0]<b[0] and a[1]>b[1]) or (a[0]>b[0] and a[1]<b[1]):        return 1    else:        return 0inname = "input.txt"outname = "output.txt"if len(sys.argv)>1:    inname = sys.argv[1]    outname = inname.rstrip(".in")    outname = outname + ".out"fin = open(inname,"r")fout = open(outname,"w")testCaseNum = int(fin.readline().rstrip("\n"))for caseNum in range(testCaseNum):    wireNum = int(fin.readline().rstrip("\n"))    wireData = []    for wireCnt in range(wireNum):        wire = [int(val) for val in fin.readline().rstrip("\n").split()]        wireData.append(wire)    crossCnt = 0    for i in range(wireNum):        for j in range(i+1,wireNum):            crossCnt = crossCnt + compareWire(wireData[i],wireData[j])    answer = "Case #%d: %d\n" %(caseNum+1,crossCnt)    fout.write(answer)fin.close()fout.close()

測試通過。不過在測試large case的時候時間有點長，有更快的演算法嗎？