Actualmente estoy escribiendo un código de recocido simulado para resolver un problema de vendedor ambulante y he tenido dificultades para almacenar y usar mis datos leídos de un archivo txt. Cada fila y columna del archivo representa cada ciudad, con la distancia entre dos ciudades diferentes almacenadas como una matriz de 15 x 15:

0.0 5.0 5.0 6.0 7.0 2.0 5.0 2.0 1.0 5.0 5.0 1.0 2.0 7.1 5.0
5.0 0.0 5.0 5.0 5.0 2.0 5.0 1.0 5.0 6.0 6.0 6.0 6.0 1.0 7.1
5.0 5.0 0.0 6.0 1.0 6.0 5.0 5.0 1.0 6.0 5.0 7.0 1.0 5.0 6.0
6.0 5.0 6.0 0.0 5.0 2.0 1.0 6.0 5.0 6.0 2.0 1.0 2.0 1.0 5.0
7.0 5.0 1.0 5.0 0.0 7.0 1.0 1.0 2.0 1.0 5.0 6.0 2.0 2.0 5.0
2.0 2.0 6.0 2.0 7.0 0.0 5.0 5.0 6.0 5.0 2.0 5.0 1.0 2.0 5.0
5.0 5.0 5.0 1.0 1.0 5.0 0.0 2.0 6.0 1.0 5.0 7.0 5.0 1.0 6.0
2.0 1.0 5.0 6.0 1.0 5.0 2.0 0.0 7.0 6.0 2.0 1.0 1.0 5.0 2.0
1.0 5.0 1.0 5.0 2.0 6.0 6.0 7.0 0.0 5.0 5.0 5.0 1.0 6.0 6.0
5.0 6.0 6.0 6.0 1.0 5.0 1.0 6.0 5.0 0.0 7.0 1.0 2.0 5.0 2.0
5.0 6.0 5.0 2.0 5.0 2.0 5.0 2.0 5.0 7.0 0.0 2.0 1.0 2.0 1.0
1.0 6.0 7.0 1.0 6.0 5.0 7.0 1.0 5.0 1.0 2.0 0.0 5.0 6.0 5.0
2.0 6.0 1.0 2.0 2.0 1.0 5.0 1.0 1.0 2.0 1.0 5.0 0.0 7.0 6.0
7.0 1.0 5.0 1.0 2.0 2.0 1.0 5.0 6.0 5.0 2.0 6.0 7.0 0.0 5.0
5.0 7.0 6.0 5.0 5.0 5.0 6.0 2.0 6.0 2.0 1.0 5.0 6.0 5.0 0.0

Para leer esto, tengo una función LoadCities () como se muestra a continuación:

#include "iostream"
#include "fstream"      
#include "string"   
using namespace std;

double distances [15][15];  

void LoadCities()
{
    ifstream CityFile;

    if (!CityFile.is_open()) //check is file has been opened
    {
        CityFile.open ("Cities.txt", ios::in | ios::out);

        if (!CityFile)
        {
            cerr << "Failed to open " << CityFile << endl;
            exit(EXIT_FAILURE);  //abort program
        }
    }

    int length;
    char * buffer;
    string cities;

    CityFile.seekg(0, ios::end);
    length = CityFile.tellg();
    CityFile.seekg (0, ios::beg);

    buffer = new char [length];

    cities = CityFile.read (buffer,length); 

    string rows = strtok(cities, "\n");

    distances = new double[rows.length()][rows.length()];

            for (int i = 0; i < (string) rows.length(); i++)
            {
                string distance = strtok(rows[i], " ");

                for (int j = 0; j < distance.length(); j++)
                {
                    distances[i][j] = (double) Parse(distance[j]);
                }
            }

    CityFile.close();
}

He intentado un método alternativo istreambuf_iterator para llegar al punto de manipular el material leído en matrices, sin embargo, siempre parece tener complicaciones:

ifstream CityFile("Cities.txt");
string theString((std::istreambuf_iterator<char>(CityFile)), std::istreambuf_iterator<char>());

Cualquier ayuda sería muy apreciada. ¡He estado golpeándome la cabeza contra esto con poco éxito!

################ EDITAR / Actualizar

@ SoapBox - Algunos detalles del código SA, funciones y main (). Esto no es limpio, eficiente, ordenado y no debe ser en esta etapa, solo necesita trabajar por el momento. Esta versión (a continuación) funciona y está configurada para resolver polinomios (problemas más simples). Lo que hay que hacer para convertirlo en un problema de vendedor ambulante es:

Escriba la función LoadCities () para recopilar los datos de distancia. (Corriente

Change Initialise () para obtener el total de las distancias involucradas

Cambie E () a la función TSP (por ejemplo, Calcular la distancia de una ruta aleatoria)

Los dos últimos que sé que puedo hacer, sin embargo, necesito LoadCities () para hacerlo. No es necesario cambiar nada más en el siguiente script.

#include "math.h"
#include "iostream"
#include "fstream"
#include "time.h"   // Define time()
#include "stdio.h"  // Define printf()
#include "randomc.h"    // Define classes for random number generators
#include "mersenne.cpp" // Include code for the chosen random number generator

using namespace std; // For the use of text generation in application

double T;
double T_initial;

double S;
double S_initial;
double S_current;
double S_trial;

double E_current;

int N_step;        // Number of Iterations for State Search per Temperature
int N_max;         //Number of Iterations for Temperature
int Write;

const double EXP = 2.718281828;

//------------------------------------------------------------------------------
//Problem Function of Primary Variable (Debugged 17/02/09 - Works as intended)

double E(double x) //ORIGNINAL
{
    double y = x*x - 6*x + 2;

     return y;
}

//------------------------------------------------------------------------------
//Random Number Generation Function (Mod 19/02/09 - Generated integers only & fixed sequence)

double Random_Number_Generator(double nHigh, double nLow) 
{
    int seed = (int)time(0);            // Random seed

    CRandomMersenne RanGen(seed);       // Make instance of random number generator

    double fr;                          // Random floating point number

    fr = ((RanGen.Random() * (nHigh - nLow)) + nLow);   // Generatres Random Interger between nLow & nHigh

    return fr;
}

//------------------------------------------------------------------------------
//Initializing Function (Temp 17/02/09)

void Initialize() //E.g. Getting total Distance between Cities
{
    S_initial = Random_Number_Generator(10, -10);

    cout << "S_Initial: " << S_initial << endl;
}

//------------------------------------------------------------------------------
//Cooling Schedule Function (make variables) (Completed 16/02/09)

double Schedule(double Temp, int i) // Need to find cooling schedule
{
    double CoolingRate = 0.9999;

    return Temp *= CoolingRate; 
}

//------------------------------------------------------------------------------
//Next State Function (Mod 18/02/09)

double Next_State(double T_current, int i)
{
        S_trial = Random_Number_Generator(pow(3, 0.5), pow(3, 0.5)*-1); 

        S_trial += S_current;

        double E_t = E(S_trial);
        double E_c = E(S_current);

        double deltaE = E_t - E_c;                              //Defines gradient of movement

        if ( deltaE <= 0 )                                      //Downhill
        {    
            S_current = S_trial;
            E_current = E_t;
        }
        else                                                    //Uphill
        {
            double R = Random_Number_Generator(1,0);            //pseudo random number generated
            double Ratio = 1-(float)i/(float)N_max;             //Control Parameter Convergence to 0
            double ctrl_pram = pow(EXP, (-deltaE / T_current)); //Control Parameter

            if (R < ctrl_pram*Ratio)                            //Checking 
            {   
                S_current = S_trial;                            //Expresses probability of uphill acceptance
                E_current = E_t;                                
            }
            else 
                E_current = E_c;
        }

        return S_current;
}

//------------------------------------------------------------------------------
//Metropolis Function (Mod 18/02/09)

double Metropolis(double S_start, double T_current, int N_Steps, int N_temperatures)
{
     S_current = S_start;                                       //Initialised S_initial equated to S_current

     for ( int i=1; i <= N_step; i++ )                          //Iteration of neighbour states
        S_current = Next_State(T_current, N_temperatures);      //Determines acceptance of new states

     return S_current;
}

//------------------------------------------------------------------------------
//Write Results to Notepad (Completed 18/02/09)

void WriteResults(double i, double T, double x, double y)
{
//This function opens a results file (if not already opened)
//and stores results for one time step

    static ofstream OutputFile;
    const int MAXLENGTH = 80;

    if (!OutputFile.is_open()) //check is file has been opened
    {
        //no it hasn't. Get a file name and open it.
        char FileName[MAXLENGTH];

        //read file name
        cout << "Enter file name: ";
        do
        {
            cin.getline(FileName, MAXLENGTH);
        }
        while (strlen(FileName) <= 0); //try again if length of string is 0

        //open file
        OutputFile.open(FileName);

        // check if file was opened successfully
        if (!OutputFile)
        {
            cerr << "Failed to open " << FileName << endl;
            exit(EXIT_FAILURE);  //abort program
        }

        OutputFile << "Iterations" << '\t' << "Temperatures" << '\t' << "X-Value" << '\t' << "Y-Value" << endl; 
        OutputFile << endl;
    }

    //OutputFile.width(10);
    OutputFile << i << '\t' << T << '\t' << x << '\t' << y << endl; 

    if (i == N_max) 
    {   
        OutputFile << endl
               << "Settings: " << endl
               << "Initial Temperature: " << T_initial << endl
               << "Temperature Iterations: " << N_max << endl
               << "Step Iterations: " << N_step << endl
               << endl
               << "Results: " << endl
               << "Final Temperature: " << T << endl 
               << "Minimum: " << S << endl;

        OutputFile.close();
    }
}

//------------------------------------------------------------------------------
//Main SA Function (Mod 17/02/09)

void SA(int W)
{
    S = S_initial;
    T = T_initial;

    for ( int N_temperatures = 1 ; N_temperatures <= N_max ; N_temperatures++ )
    {
        S = Metropolis( S, T, N_step, N_temperatures);
        T = Schedule(T, N_temperatures);

        if (W == 1)
            WriteResults(N_temperatures, T, S, E_current);
    }

    cout << "Result" << endl
    << "Y-value> " << S << endl
    << "Temperature> " << T << endl;

}

//------------------------------------------------------------------------------
//Execution of Traveling Salesman Problem (Progress 18/02/09)


int main()
{
    cout << "Quadratic Function" << endl
         << "Solving method: Simulated Annealing" << endl;
    cout << "" << endl;

    cout << "Select desired Initial Temperature:" << endl
         << "> ";
    cin >> T_initial;

    cout << "Select desired number of Temperature Iterations:" << endl
         << "> ";
    cin >> N_max;

    cout << "Select desired number of step Iterations:" << endl
         << "> ";
    cin >> N_step;

    Initialize();

    cout << "Write to file: (1 / 0) " << endl
         << "> ";
    cin >> Write;

    SA(Write);

    system ("PAUSE");

    return 0;
}

@ strager: conozco su código incorrecto, pero desafortunadamente con las limitaciones de tiempo involucradas para mi proyecto y la curva de aprendizaje consistente, ¡los resultados son lo que se necesitan! :) Se ordenará en las últimas etapas.

@ dirkgently: esa fue la razón inicial para hacerlo de esta manera, y por eso mi primer intento es hacerlo así.