1 #include <iostream> 2 #include <fstream> 3 #include <cstring> 4  5 using namespace std; 6  7 void reverse( char *str ); 8  9 int main( int argc, char *argv[] ) {10     string data_file = "./1.2.txt";11     ifstream ifile( data_file.c_str(), ios::in );12     if( !ifile.is_open() ) {13         fprintf( stderr, "cannot open file: %s\n", data_file.c_str() );14         return -1;15     }16     char buffer[1000];17     while( ifile.getline( buffer, 999 ) ) {18         cout <<buffer <<": ";19         reverse( buffer );20         cout <<buffer <<endl;21     }22     ifile.close();23     return 0;24 }25 26 void reverse( char *s ) {27     int slen = strlen( s );28     for( int i = 0; i < slen/2; ++i ) {29         swap( s[i], s[slen-i-1] );30     }31     return;32 }

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