首页 > 试题广场 >

String Matching

[编程题]String Matching

热度指数：11045 时间限制：C/C++ 1秒，其他语言2秒空间限制：C/C++ 64M，其他语言128M
算法知识视频讲解

Finding all occurrences of a pattern in a text is a problem that arises frequently in text-editing programs. Typically,the text is a document being edited,and the pattern searched for is a particular word supplied by the user. We assume that the text is an array T[1..n] of length n and that the pattern is an array P[1..m] of length m<=n.We further assume that the elements of P and T are all alphabets(∑={a,b...,z}).The character arrays P and T are often called strings of characters. We say that pattern P occurs with shift s in the text T if 0<=s<=n and T[s+1..s+m] = P[1..m](that is if T[s+j]=P[j],for 1<=j<=m). If P occurs with shift s in T,then we call s a valid shift;otherwise,we calls a invalid shift. Your task is to calculate the number of vald shifts for the given text T and p attern P.

输入描述:

   For each case, there are two strings T and P on a line,separated by a single space.You may assume both the length of T and P will not exceed 10^6.

输出描述:

    You should output a number on a separate line,which indicates the number of valid shifts for the given text T and pattern P.

示例1

输入

abababab abab

输出

算法知识视频讲解

Python

华科平凡


while True:
    try:
        a,b=input().split()
        res,judge=0,[]
        for i,v in enumerate(a[:len(a)-len(b)+1]):
            if v==b[0]:judge.append(i)
        for i in judge:
            if a[i:i+len(b)]==b:res+=1
        print(res)
    except:
        break