Priority Queue implementation in C++ (#77)

Author: Ps1231

priorityQueue.cpp

@@ -0,0 +1,171 @@
+#include <iostream>
+#include <stdio.h>
+#include <cstring>
+using namespace std;
+struct data
+{
+    char job[10];
+    int prno , ord;
+
+};
+const int MAX=5;
+class priority_queue
+{
+    private:
+            data d[MAX];
+            int front,rear;
+    public:
+            priority_queue()
+            {
+                front=rear=-1;
+                for(int i=0;i<MAX;i++)
+                {
+                    strcpy(d[i].job,"\0");
+                    d[i].prno=d[i].ord=0;
+                }
+            }
+            void add(data dt)
+            {
+                if(rear==MAX-1)
+                {
+                    cout<<"Queue is full";
+                }
+                else
+                {
+                    rear++;
+                    d[rear]=dt;
+                    if(front==-1)
+                    {   front=0; }
+
+                }
+
+            }
+            void remove()
+            {   
+                int highestPriority = 0;
+                int ind = -1;
+                data temp;
+                for(int i=front;i<=rear;i++)
+                {
+                    if (highestPriority == d[i].prno && ind > -1 && d[ind].job < d[i].job) 
+                    {
+                        highestPriority = d[i].prno;
+                        ind = i;
+                    }
+                    else if (highestPriority < d[i].prno) 
+                    {
+                        highestPriority = d[i].prno;
+                        ind = i;
+                    }
+                }
+
+                if(front==-1)
+                {
+                    cout<<"Queue is empty";
+
+                }
+
+                else
+                {
+                        for(int i=ind;i<rear;i++)
+                        {
+                            d[i] = d[i + 1];
+
+                        }
+
+                }
+                rear--;
+            }
+
+            void sort()
+            {
+                data temp;
+                for(int i=front;i<rear;i++)
+                {
+                    for(int j=i+1; j<=rear;j++)
+                    {
+                        if(d[i].prno>d[j].prno)
+                        {
+                            temp=d[i];
+                            d[i]=d[j];
+                            d[j]=temp;
+                        }
+                        else if(d[i].prno==d[j].prno)
+                        {
+                            if(d[i].ord>d[j].ord)
+                            {
+                                temp=d[i];
+                                d[i]=d[j];
+                                d[j]=temp;
+                            }
+                        }
+                    }
+                }
+                display();
+            }
+
+            void display()
+            {
+                if(front==-1)
+                {
+                    cout<<"Queue is empty";
+                }
+                else
+                {
+                    for(int i=front;i<=rear;i++)
+                    {
+                        cout<<d[i].job<<" ";
+                    }
+                }
+                cout<<endl;
+            }
+};
+int main ()
+{
+    priority_queue p;
+    int ord=0;
+    while(true)
+    {
+        cout<< "Priority Queue Operations :- "<<endl;
+        cout<< "1 -> ADD"<<endl;//add element at end
+        cout<< "2 -> REMOVE "<<endl; //removes element from front
+        cout<< "3 -> DISPLAY"<<endl;//display all the elements
+        cout<< "4 -> SORT BY PRIORITY "<<endl;
+        cout<< "5 -> EXIT"<<endl;
+          int c;
+        cout<<"Enter your choice :";
+        cin >>c;
+        switch(c)
+        {
+            case 1:
+                data d;
+                cout<<"Enter the data : ";
+                cin >>d.job;
+                cout<<"Enter the Priority no : ";
+                cin >>d.prno;
+                d.ord=ord++;
+                p.add(d);
+                break;
+            case 2:
+                p.remove();
+                break;
+            case 3:
+                p.display();
+                break;
+            case 4:
+                p.sort();
+                break;
+            case 5:
+                exit(0);
+            default:
+                cout<<"Invalid Input"<<endl;
+                false;
+                break;
+
+
+        }
+    }
+
+
+return 0 ;  
+}