metro.cpp

#include <iostream>
#include <unordered_map>
#include <vector>
#include <queue>
#include <climits>

using namespace std;

// ANSI Colors
#define BLUE "\033[34m"
#define YELLOW "\033[33m"
#define RED "\033[31m"
#define GREEN "\033[32m"
#define RESET "\033[0m"

class Graph{

public:

unordered_map<string, vector<pair<string,int>>> adj;
unordered_map<string,string> lineColor;

void addStation(string name,string color){

lineColor[name]=color;

}

void addEdge(string u,string v,int w){

adj[u].push_back({v,w});
adj[v].push_back({u,w});

}

void displayStations(){

cout<<"\n====== DELHI METRO STATIONS ======\n\n";

for(auto &x:adj){

string station=x.first;
string color=lineColor[station];

if(color=="BLUE")
cout<<BLUE<<station<<RESET<<endl;

else if(color=="YELLOW")
cout<<YELLOW<<station<<RESET<<endl;

else if(color=="RED")
cout<<RED<<station<<RESET<<endl;

else
cout<<station<<endl;

}

}

void shortestPath(string src,string dest){

unordered_map<string,int> dist;
unordered_map<string,string> parent;

for(auto &x:adj)
dist[x.first]=INT_MAX;

priority_queue<
pair<int,string>,
vector<pair<int,string>>,
greater<pair<int,string>>> pq;

dist[src]=0;
pq.push({0,src});

while(!pq.empty()){

auto node=pq.top();
pq.pop();

int cost=node.first;
string u=node.second;

for(auto &nbr:adj[u]){

string v=nbr.first;
int weight=nbr.second;

if(cost+weight < dist[v]){

dist[v]=cost+weight;
parent[v]=u;

pq.push({dist[v],v});
}

}

}

cout<<"\nShortest Distance: "<<dist[dest]<<" km\n";

vector<string> path;

string cur=dest;

while(cur!=src){

path.push_back(cur);
cur=parent[cur];

}

path.push_back(src);

cout<<"\nRoute:\n";

for(int i=path.size()-1;i>=0;i--){

string station=path[i];
string color=lineColor[station];

if(color=="BLUE")
cout<<BLUE<<station<<RESET;

else if(color=="YELLOW")
cout<<YELLOW<<station<<RESET;

else if(color=="RED")
cout<<RED<<station<<RESET;

else
cout<<station;

if(i!=0)
cout<<" -> ";

}

cout<<endl;

}

};

void createMetro(Graph &g){

// Blue line stations

g.addStation("Noida Sector 62","BLUE");
g.addStation("Botanical Garden","BLUE");
g.addStation("Yamuna Bank","BLUE");
g.addStation("Rajiv Chowk","BLUE");
g.addStation("Moti Nagar","BLUE");
g.addStation("Janakpuri West","BLUE");
g.addStation("Dwarka Sector 21","BLUE");

// Yellow line

g.addStation("AIIMS","YELLOW");
g.addStation("Saket","YELLOW");
g.addStation("Hauz Khas","YELLOW");
g.addStation("Chandni Chowk","YELLOW");
g.addStation("New Delhi","YELLOW");

// Red line

g.addStation("Kashmere Gate","RED");
g.addStation("Shastri Park","RED");
g.addStation("Seelampur","RED");

// Connections

g.addEdge("Noida Sector 62","Botanical Garden",8);
g.addEdge("Botanical Garden","Yamuna Bank",10);
g.addEdge("Yamuna Bank","Rajiv Chowk",6);
g.addEdge("Rajiv Chowk","Moti Nagar",9);
g.addEdge("Moti Nagar","Janakpuri West",7);
g.addEdge("Janakpuri West","Dwarka Sector 21",6);

g.addEdge("Rajiv Chowk","New Delhi",1);
g.addEdge("New Delhi","Chandni Chowk",2);
g.addEdge("Rajiv Chowk","AIIMS",7);
g.addEdge("AIIMS","Hauz Khas",3);
g.addEdge("Hauz Khas","Saket",2);

g.addEdge("Chandni Chowk","Kashmere Gate",2);
g.addEdge("Kashmere Gate","Shastri Park",3);
g.addEdge("Shastri Park","Seelampur",2);

}

int main(){

Graph g;

createMetro(g);

int choice;

while(true){

cout<<"\n===== DELHI METRO APP =====\n";
cout<<"1 Show Stations\n";
cout<<"2 Shortest Route\n";
cout<<"3 Exit\n";

cin>>choice;

if(choice==1){

g.displayStations();

}

else if(choice==2){

string src,dest;

cin.ignore();

cout<<"Enter Source: ";
getline(cin,src);

cout<<"Enter Destination: ";
getline(cin,dest);

g.shortestPath(src,dest);

}

else if(choice==3){

break;

}

}

}