统计单词数（C++stl str.find()函数）

Problem G: 统计单词数

输入样例1：
To
to be or not to be is a question
输入样例2：
to
Did the Ottoman Empire lose its power at that time

输出样例1：
2 0
输出样例2：
-1

#include<cstdio>
#include<cstring>
#include<string>
#include<sstream>
#include<set>
#include<iostream>
using namespace std;
int main()
{
    string s,word;
    int i,m,num1,flag,num2,m1;
    while(cin>>s)
    {
       getchar();
       num2=-1;
       flag=num1=m=0;
       for(i=0;i<s.length();i++)
       {
           if(isalpha(s[i]))
           {
               s[i]=tolower(s[i]);
           }
       }
       s=' '+s+' ';
      // cout<<s<<endl;
       getline(cin,word);
      // cout<<word<<endl;
        for(i=0;i<word.length();i++)
        {
            if(isalpha(word[i]))
            {
                word[i]=tolower(word[i]);
            }
        }
        word=' '+word+' ';
       m=word.find(s);
       while(m!=string::npos)
       {
            num1++;
            if(flag==0)
            {
                num2=m;
                flag=1;
            }
           m=word.find(s,m+1);
       }
     //  cout<<num1<<" "<<num2<<endl;
       if(num2==-1)
       {
           cout<<-1<<endl;
       }
       else
       {
           cout<<num1<<" "<<num2<<endl;
       }
    }
}

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