1. String operation.cpp

#include<iostream>
#include<string>
#include<stdlib.h>
using namespace std;
int main()
{
    string str="somewhere, something incredible is waiting to be known.";


    cout<<"Find some from first: "<<str.find("some")<<endl;
    cout<<"Find some from last: "<<str.rfind("some")<<endl;


    cout<<"substring: "<<str.substr(0,9)<<endl;
    cout<<"substring: "<<str.substr(11,9)<<endl;

    cout<<"lexicographically small: "<<min(str.substr(0,9),str.substr(11,9))<<endl;
    cout<<"lexicographically large: "<<max(str.substr(0,9),str.substr(11,9))<<endl;

    return 0;
}

2. output

Find some from first: 0
Find some from last: 11
substring: somewhere
substring: something
lexicographically small: something
lexicographically large: somewhere