Added Dijkstra's Algorithm in cpp

Author: arpit7714

C++/Algorithms/Graph-Algorithms/Dijkstra's Algorithm.cpp

@@ -0,0 +1,87 @@
+/* A C++ program for Dijkstra's algorithm. The program Used
+the adjacency matrix 
+Ask the input from the user the num of edges, 
+num of vertices and the graph with the value of each edge
+It will print the minimum cost from source to destination
+
+Nodes should be provided from the index 1
+
+*/
+#include <bits/stdc++.h>
+using namespace std;
+struct compare{
+ bool operator()(pair<int, int>&a, pair<int, int>&b){
+ return a.first > b.first;
+ }
+ };
+
+int findMinPath(vector<vector<int>>& graph, int n, int src, int dest){
+ vector<int>distance(n, INT_MAX);//it will the shortest distance from source to every node
+
+ vector<bool>visited(n, false);
+
+ distance[src] = 0;
+
+ priority_queue<pair<int, int>, vector<pair<int, int>>, compare>qt;
+
+ int connect = 0;
+
+ int i = src;
+ int total = 0;
+
+ //loop will work untill reach the destination
+ while( i != dest ){
+
+ visited[i] = true;
+ 
+ int j = 0;
+
+ while(j < n){
+ if (!visited[j] && graph[i][j]!=-1 && distance[i]!=INT_MAX && distance[i] + graph[i][j] < distance[j]){
+ distance[j] = distance[i] + graph[i][j];
+ qt.push(make_pair(distance[j], j));
+ }
+ j++;
+ }
+
+ //pop the mini value from the priority queue
+ int dis = qt.top().first; 
+ cout << dis << "\n";
+
+ total = dis;
+
+ i = qt.top().second;
+ qt.pop();
+ }
+ return total;
+
+}
+int main(){
+ int num_vertices;
+ cin >> num_vertices;
+ 
+ int num_edges;
+ cin >> num_edges; 
+ vector<vector<int>>graph(num_vertices, vector<int>(num_vertices, -1));
+
+ int a, b, val;
+ for(int i=0;i<num_edges;i++){
+ cin >> a;
+ cin >> b;
+ cin >> val;
+ graph[a-1][b-1] = val;
+ graph[b-1][a-1] = val;
+ }
+ int source_vertex;
+ cin >> source_vertex;
+
+ int dest_vertex;
+ cin >> dest_vertex;
+
+ 
+ int min_cost = findMinPath(graph, num_vertices, source_vertex-1, dest_vertex-1);
+
+ cout << "Minimum cost of total Path " << min_cost <<"\n";
+
+ return 0;
+}