OJ_1094

#include <iostream>
#include <string>
using namespace std;
void func()
{
     string t,p;
     while(cin>>t>>p)
     {
                     int count=0;
                     for(int i=0;i<t.size();i++)
                     {
                             if(t[i]==p[0])
                             {
                                           bool flag=true;
                                           int k=i+1;
                                           for(int j=1;j<p.size();j++)
                                           {
                                                   if(t[k++]!=p[j])
                                                   {
                                                                   flag=false;
                                                                   break;
                                                   }
                                                   
                                           }
                                           if(flag)
                                           count++;
                                           
                             }
                     }
                     cout<<count<<endl;
     }
     
   
}
int main(int argc, char *argv[])
{
    
	//printf("Hello, world\n");
	func();
	return 0;
}

顺序扫描

题目描述：

    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：

   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：

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

样例输入：

abababab abab

样例输出：

3