KMP初试

参考博客：http://jakeboxer.com/blog/2009/12/13/the-knuth-morris-pratt-algorithm-in-my-own-words/
参考博客：http://www.cnblogs.com/c-cloud/p/3224788.html
1.）求nexts数组：

[root@VM_131_54_centos kmp]# python nexts.py [0, 0, 1, 2, 3, 4][0, 0, 1, 2, 3, 4, 0, 1][root@VM_131_54_centos kmp]# cat nexts.py def getNext(s):    nexts=[]    nexts.append(0)    l = len(s)    for x in range(1,l):        d = 0        ss = s[:x+1]        for y in range(0,x):            if ss[:y] == ss[-y:]:                d = y        nexts.append(d)    return nextsprint getNext("bababa")print getNext("abababca")   

下面试下求解匹配到的次数：

[root@VM_131_54_centos kmp]# python n.py313100:00:00.000122[root@VM_131_54_centos kmp]# cat n.py#encoding:utf-8import datetimestarttime = datetime.datetime.now()import sysdef getNext(s):    nexts=[]    nexts.append(0)    l = len(s)    for x in range(1,l):        d = 0        ss = s[:x+1]        for y in range(0,x):            if ss[:y] == ss[-y:]:                d = y        nexts.append(d)    return nexts#子串在父串中出现几次：#移动步长 = 匹配字符个数 - 最后匹配成功的字符在nexts数组中对应的值def counts(a,s,n):    la = len(a)    ls = len(s)    j = 0    count = 0    while True:        for i in range(1,ls+1):            if s[i-1] == a[j+i-1]:                 if ls ==i:                    j += i - n[i-1]                    count +=1            else:                j += i - n[i-1]                 break        if (la-j) < ls:            break       return count'''all = []t = int(raw_input())for x in range(0,t):    s = raw_input()    a = raw_input()    all.append([s,a])for x in range(0,t):    n = getNext(all[x][0])    print counts(all[x][1],all[x][0],n)'''s = "HA"a = 'HAHAHA'n = getNext(s)print counts(a,s,n)s = "WQN"a = 'WQN'n = getNext(s)print counts(a,s,n)s = "ADA"a = 'ADADADA'n = getNext(s)print counts(a,s,n)s = "BABABB"a = 'BABABABABABABABABB'n = getNext(s)print counts(a,s,n)s = "DAD"a = 'ADDAADAADDAAADAAD'n = getNext(s)print counts(a,s,n)endtime = datetime.datetime.now()print (endtime-starttime)

但是 改为获取用户输入时，TLE了。再改。不知道哪里出问题了。