Creating dijkstra's algo implementation in cpp

Author: rudradesai200

Dijkstra/dijkstras.cpp

@@ -0,0 +1,64 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int findmin(vector<int> dist,int N,std::vector<int> &freq){
+  int mint;
+  for(int i=0;i<N;i++){if(freq[i] == 0){mint = i;break;}}
+  for(int i=0;((i<N));i++){
+    if((freq[i]==0)){
+    if(dist[mint]>dist[i]){mint = i;}
+  }
+  }
+  freq[mint] = 1;
+  return mint;
+}
+
+void printvector(std::vector<int> v,int N){
+  for(int i=0;i<N;i++)cout<<v[i]<<' ';
+  cout<<endl;
+}
+void dijkstras(vector<int> &dist,std::vector<std::vector<int> > l,vector<int> &prev,int N){
+  // printvector(dist,N);
+  vector<int> freq;
+  for(int i=0;i<N;i++){freq.push_back(0);}
+  dist[0] = 0;
+  for(int j=0;j<N;j++){
+    int u = findmin(dist,N,freq);
+    for(int i=0;i<N;i++){
+      if(l[u][i] != -1){
+        if(dist[i] > (dist[u] + l[u][i])){
+          dist[i] = (dist[u] + l[u][i]);
+          prev[i] = u;
+        }
+      }
+    }
+    // printvector(dist,N);
+  }
+}
+int main(){
+  int N;cin>>N;
+  vector<int> dist,prev;
+  vector<vector<int>> l;
+  int E;cin>>E;
+
+  vector<int> temp;
+  for(int i =0;i<N;i++){
+    temp.push_back(-1);
+    dist.push_back(INT_MAX);
+    prev.push_back(-1);
+  }
+  for(int i=0;i<N;i++){
+    l.push_back(temp);
+  }
+
+  for(int i=0;i<E;i++){
+    int a,b,d;cin>>a>>b>>d; //format is a --(d)--> b represents an edge
+    l[a-1][b-1] = d;
+    // l[b][a] = d;
+  }
+
+  dijkstras(dist,l,prev,N);
+
+  printvector(prev,N);
+}