rparse.cpp

Think in C++ 第二版源码

//: C17:Rparse.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Reverse the order of words in a string
#include <string>
#include <iostream>
#include <vector>
using namespace std;

int main() {
  // The ';' characters will be delimiters
  string s("now.;sense;make;to;going;is;This");
  cout << s << endl;
  // To store the words:
  vector<string> strings;
  // The last element of the string:
  int last = s.size();
  // The beginning of the current word:
  int current = s.rfind(';');
  // Walk backward through the string:
  while(current != string::npos){
    // Push each word into the vector.
    // Current is incremented before copying to 
    // avoid copying the delimiter.
    strings.push_back(
      s.substr(++current,last - current));
    // Back over the delimiter we just found, 
    // and set last to the end of the next word
    current -= 2;
    last = current;
    // Find the next delimiter
    current = s.rfind(';', current);
  }
  // Pick up the first word - it's not 
  // preceded by a delimiter
  strings.push_back(s.substr(0, last - current));
  // Print them in the new order:
  for(int j = 0; j < strings.size(); j++)
    cout << strings[j] << " ";
} ///:~