string专题练习

//jz1036

#include<iostream>
#include<string>
#include<cctype>
using namespace std;
int main(){
    string s;
    int a,b,c;
    a=b=c=0;
    cin>>s;
    for(int i=0;i<s.size();i++){
        if(s[i]>='A' && s[i]<='Z')a++;
        if(s[i]>='a' && s[i]<='z')b++;
        if(s[i]>='0' && s[i]<='9')c++;
    }
    cout<<a<<' '<<b<<' '<<c<<endl;
    return 0;
}

　　 

#include<iostream>
#include<string>
#include<cctype>
using namespace std;
int main(){
    string s;
    int a,b,c;
    a=b=c=0;
    cin>>s;
    for(int i=0;i<s.size();i++){
        if(isupper(s[i]))a++;
        if(islower(s[i]))b++;
        if(isdigit(s[i]))c++;
    }
    cout<<a<<' '<<b<<' '<<c<<endl;
    return 0;
}

　　

//1583

#include<iostream>
#include<string>
#include<cctype>
using namespace std;
int main(){
    string s;
    getline(cin,s);
    //cin>>s;  //不行 
    for(int i=s.size()-1;i>=0;i--)cout<<s[i];
    cout<<endl;
    return 0;
}

　　

#include<iostream>
#include<string>
#include<cctype>
#include<algorithm>
using namespace std;
int main(){
    string s;
    getline(cin,s);
    //cin>>s;  //不行 
    reverse(s.begin(),s.end());
    cout<<s<<endl;
    return 0;
}