std::out_of_range在字符串向量中搜索匹配项时发生异常

试试这个：

  for (unsigned int f2 = 0; f2 < flights.size(); f2++) {
     //store all the fligths that match the departure airport into deptMatches
     string code = flights[f2];
     if (code.length() > 7 && airpCode2 == flights[f2].substr(4, 3)) { //the call stack says the error is at this line 
    destMatches.push_back(flights[f2]);
     }
  }

这就是我会做的：

   vector<string>::iterator iter = flights.begin(); 
   for (; iter!=flights.end(); ++iter) {
      istringstream is(*iter);
      string tokens[5];
      for (unsigned int i=0; i<5; ++i) {
     is >> tokens[i];
      }
      if (tokens[0] == airpCode1) {
     deptMatches.push_back(*iter);
      }
      if (tokens[1] == airpCode2) {
     destMatches.push_back(*iter);
      }
   }

您应该查找"传递闭包"和Warshall的算法。我想我下面的代码可以做你想做的事情。

#include <string>
#include <iostream>
#include <set>
#include <vector>
#include <sstream>
#include <stdexcept>
// if you prefer to 'weight' your search on time
// uncomment time and comment price
#define PRICE
//#define TIME
using namespace std;
static const size_t NUMFLIGHTS=6;
static const char* data[] {
   "EMA CDG BritishAirways 120 100",
      "CDG VIE AirFrance 120 100",
      "EMA VIE BritishAirways 150 300",
      "EMA CDG AirFance 130 80",
      "GRO FFF Rayanair 130 80",
      "FFF HHH AirItalia 100 50"};
struct flight {
   void set(const string& input) {
      istringstream is(input);
      is >> dept >> dest >> airways >> time >> price;
   }
   string dept;
   string dest;
   string airways;
   unsigned int time;
   unsigned int price;
};
struct travelData {
   travelData() : weight(0), infinity(true) {}
   vector<flight> flights;
   unsigned int weight;
   bool infinity;
   void print() {
      auto i=flights.begin();
      for (;i!=flights.end(); ++i) {
     cout << i->dept << " " << i->dest << endl;
      }
      cout << weight << endl;
   }
};
struct database {
   vector< vector<travelData> > allflights;
   flight flights[NUMFLIGHTS];
   vector<string> locations;
};

travelData FlightExists(const flight* flights, const string& dept, const string& dest) {
   travelData ret;
   for (size_t i=0; i<NUMFLIGHTS; ++i) {
      if (flights[i].dest == dest && flights[i].dept == dept) {
     ret.flights.push_back(flights[i]);
#ifdef PRICE
     ret.weight = flights[i].price;
#elif LENGTH
     ret.weight = flights[i].time;
#else
     ret.weight = 1;
#endif
     ret.infinity= false;
     return ret;
      }
   }
   return ret;
}

database setup()
{
   database ret;
   set<string> locationsSet;
   for (size_t i=0; i<NUMFLIGHTS; ++i) {
      ret.flights[i].set(data[i]);
      locationsSet.insert(ret.flights[i].dept);
      locationsSet.insert(ret.flights[i].dest);
   }
   copy(locationsSet.begin(), locationsSet.end(), back_inserter(ret.locations));
   size_t len = ret.locations.size();
   for (size_t i=0; i<len; ++i) {
      string searchDept = ret.locations[i];
      vector<travelData> row;
      for (size_t j=0; j<len; ++j) {
     string searchDest = ret.locations[j];
     if (i == j) {
        travelData blank;
        blank.infinity = false;
        row.push_back(blank);
     } else {
        row.push_back(FlightExists(ret.flights, searchDept, searchDest));
     }
      }
      ret.allflights.push_back(row);
   }
   // Warshalls algorithn
   for (size_t k=0; k<len; ++k) {
      for (size_t i=0; i<len; ++i) {
     for (size_t j=0; j<len; ++j) {
        travelData& d = ret.allflights[i][j];
        travelData& s1 = ret.allflights[i][k];
        travelData& s2 = ret.allflights[k][j];
        if (!s1.infinity && !s2.infinity) {
           int sum = s1.weight + s2.weight;
           if (d.infinity) {
          d.infinity = false;
          d.flights.insert(d.flights.begin(), 
                   s1.flights.begin(), 
                   s1.flights.end());
          d.flights.insert(d.flights.begin(), 
                   s2.flights.begin(), 
                   s2.flights.end());
          d.weight = sum;
           } else if (d.weight > sum) {
          d.flights.clear();
          d.flights.insert(d.flights.begin(), 
                   s1.flights.begin(), 
                   s1.flights.end());
          d.flights.insert(d.flights.begin(), 
                   s2.flights.begin(), 
                   s2.flights.end());
          d.weight = sum;
           }
        }
     }
      }
   }

   return ret;

}
size_t GetIndex(const database& db, const string search) {
   size_t len = db.locations.size();
   for (size_t i=0; i<len; ++i) {
      if (db.locations[i] == search) {
     return i;
      }
   }
   throw runtime_error("bogus search");
}
travelData GetResults(const database& db, const string& dept, const string& dest) {
   travelData ret;
   size_t i_index = GetIndex(db, dept);
   size_t j_index = GetIndex(db, dest);
   return db.allflights[i_index][j_index];
}
int main() {
   database db = setup();
   travelData result = GetResults(db, "GRO", "HHH");
   result.print();
   return 0;
}