題目：https://www.patest.cn/contests/pat-a-PRactise/1071

代碼：

#include<cstdio>  #include<cstring>  #include<cstdlib> #include<cmath>#include<map>#include<string>#include<iostream>#include<algorithm>  using namespace std; bool check(char c){   if(c>='0'&&c<='9')return true;   if(c>='a'&&c<='z')return true;   if(c>='A'&&c<='Z')return true;   return false;}int main()  {   	map<string,int>s;	string str;	getline(cin,str);	int i=0;	while(i<str.length()){		string temp;		while(i<str.length()&&check(str[i])==true){			if(str[i]>='A'&&str[i]<='Z'){			     str[i]+=32;			}			temp+=str[i];			i++;		}		if(temp!=" "){			if(s.find(temp)==s.end()) s[temp]=1;			else s[temp]++;		}		while(i<str.length()&&check(str[i])==false){		  i++;		}	}	string final;	int max=0;	for(map<string,int>::iterator i=s.begin();i!=s.end();i++){		if(i->second>max){			max=i->second;			final=i->first;		}	}	cout<<final<<" "<<max<<endl;    system("pause");  }