String Replace 1.0

main.cpp

#include <iostream>
#include <string>

using namespace std;

string & replace_all ( string & str, const string & old_value, const string & new_value ) {
    while ( true ) {
        string::size_type pos ( 0 );
        if ( ( pos = str.find ( old_value ) ) != string::npos )
            str.replace ( pos, old_value.length(), new_value );
        else
            break;
    }
    return str;
}

int main ( int argc, char* argv[] ) {
    string    s1    = argv[1];
    string    s2    = argv[2];
    string    s3    = argv[3];
    cout << replace_all ( s3, s1, s2 ) << endl;
    return 0;
}

附件1