graph_formulation.cpp

#include "metro.hpp"

const int total_stations = 57;
string stations[57];
map<string, int> code;
double graph[57][57];
bool station_closed[57] = {false};
bool line_snag[3] = {false, false, false}; // RED, GREEN, BLUE technical-snag flags

void map_code() {
    // Initialize empty graph
    for(int i=0; i<total_stations; i++) {
        for(int j=0; j<total_stations; j++)
            graph[i][j] = 0.0;
        station_closed[i] = false; // reset disruption state on every (re)load
    }
    line_snag[0] = line_snag[1] = line_snag[2] = false;

    // --- RED LINE (0 to 26) ---
    string red_line[] = {"Miyapur", "JNTU_College", "KPHB_Colony", "Kukatpally", "Balanagar", "Moosapet",
                         "Bharat_Nagar", "Erragadda", "ESI_Hospital", "SR_Nagar", "Ameerpet",
                         "Punjagutta", "Irrum_Manzil", "Khairatabad", "Lakdikapul", "Assembly",
                         "Nampally", "Gandhi_Bhavan", "Osmania_Medical", "MGBS",
                         "Malakpet", "New_Market", "Musarambagh", "Dilsukhnagar", "Chaitanyapuri",
                         "Victoria_Memorial", "LB_Nagar"};
    for(int i=0; i<27; i++) {
        stations[i] = red_line[i];
        code[red_line[i]] = i;
    }

    // --- GREEN LINE (27 to 34) ---
    string green_line[] = {"JBS_Parade_Ground", "Secunderabad_West", "Gandhi_Hospital",
                           "Musheerabad", "RTC_X_Roads", "Chikkadpally", "Narayanaguda", "Sultan_Bazar"};
    for(int i=0; i<8; i++) {
        int id = 27 + i;
        stations[id] = green_line[i];
        code[green_line[i]] = id;
    }

    // --- BLUE LINE (35 to 56) ---
    string blue_line[] = {"Nagole", "Uppal", "Stadium", "NGRI", "Habsiguda", "Tarnaka",
                          "Mettuguda", "Secunderabad_East", "Parade_Ground", "Paradise",
                          "Rasoolpura", "Prakash_Nagar", "Begumpet", "Madhura_Nagar",
                          "Yusufguda", "Road_No_5", "Jubilee_Hills_Checkpost", "Peddamma_Temple",
                          "Madhapur", "Durgam_Cheruvu", "HITEC_City", "Raidurg"};
    for(int i=0; i<22; i++) {
        int id = 35 + i;
        stations[id] = blue_line[i];
        code[blue_line[i]] = id;
    }

    // Call the external file to populate the distances
    loadDistances();
}

string getLine(int id) {
    if (id >= 0 && id <= 26) return "RED Line";
    if (id >= 27 && id <= 34) return "GREEN Line";
    if (id >= 35 && id <= 56) return "BLUE Line";
    return "UNKNOWN";
}

// Numeric line index used to index line_snag[] and for fast comparisons.
int getLineIndex(int id) {
    if (id >= 0 && id <= 26) return 0;  // RED
    if (id >= 27 && id <= 34) return 1; // GREEN
    if (id >= 35 && id <= 56) return 2; // BLUE
    return -1;
}

double getActualDistance(vector<int>& path) {
    // path.size() is unsigned (size_t). If path is empty, path.size() - 1
    // underflows to a huge number and the loop below reads out of bounds.
    if (path.size() < 2) return 0.0;

    double dist = 0.0;
    for(size_t i = 0; i < path.size() - 1; i++) {
        dist += graph[path[i]][path[i+1]];
    }
    return dist;
}

// Counts how many line changes occur along a path (used for the
// transfer-walk-time penalty in schedule.cpp).
int countTransfers(vector<int>& path) {
    if (path.size() < 2) return 0;
    int transfers = 0;
    for (size_t i = 0; i + 1 < path.size(); i++) {
        if (getLine(path[i]) != getLine(path[i+1])) transfers++;
    }
    return transfers;
}