解题思路:
(1)getline(cin,s),防止空格的出现
#include<iostream>
#include<map>
using namespace std;
void helper(string &s) {
map<int,int> mp;
for(int i=0;i<s.length();i++) {
if('a'<=s[i] && s[i]<='z' ||('A'<=s[i] && s[i]<='Z')) mp[0]++;
else if(s[i]==' ') mp[1]++;
else if(isdigit(s[i])) mp[2]++;
else mp[3]++;
}
cout<<mp[0]<<endl;
cout<<mp[1]<<endl;
cout<<mp[2]<<endl;
cout<<mp[3]<<endl;
}
int main() {
string s="";
while(getline(cin,s)) {
helper(s);
}
return 0;
}