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String Matching

[编程题]String Matching

热度指数：11296 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

Java

LHC0512

Java

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()){
            String ss= scanner.next();
            String s = scanner.next();
            int i=0;
            int count=0;
            while (ss.indexOf(s,i)!=-1){
                count++;
                i=ss.indexOf(s,i)+1;
            }
            System.out.println(count);
        }
    }
}

发表于 2020-03-20 11:16:51 回复(0)