Create kruskals.cpp

kruskal's algorithm

greedy_algorithms/kruskals.cpp

@@ -0,0 +1,86 @@
+#include<iostream>
+using namespace std;
+
+void printArray(int arr[3][100],int n){
+    for(int i=0;i<3;i++){
+        for(int j=0;j<n;j++){
+            cout<<arr[i][j]<<" ";
+        }
+        cout<<endl;
+    }
+    cout<<endl;
+}
+
+void sort(int arr[3][100], int n){
+    for(int i = 0;i<n;i++){
+        for(int j=i+1;j<n;j++){
+            if(arr[0][j]<arr[0][i]){
+                int temp1 = arr[0][i],temp2 = arr[1][i],temp3 = arr[2][i];
+                arr[0][i] = arr[0][j];
+                arr[1][i] = arr[1][j];
+                arr[2][i] = arr[2][j];
+
+                arr[0][j] = temp1;
+                arr[1][j] = temp2;
+                arr[2][j] = temp3;
+                
+            }
+        }
+    }
+}
+
+int main(){
+    // sort all edges in increasing order of weights
+    // thn take each vertex and if it does not form cycle thn add it to the graph and cost
+
+    int v = 6, cost = 0, e = 0;
+    int adj[6][6] = {{0,3,0,6,0,7},{3,0,1,4,0,0},{0,1,0,5,0,0},{6,4,5,0,10,0},{0,0,0,10,0,12},{7,0,0,0,12,0}};
+    bool check[6];
+
+    for(int i=0;i<v;i++){
+        check[i] = false;
+    }
+
+    int arr[3][100];
+    // 0 => weight     1 => parent1     2 => parent2
+
+    // find all non zero weight edges
+    int k = 0, n=0;
+    for(int i=0;i<v;i++){
+        for(int j=n;j<v;j++){
+            if(adj[i][j]!=0){
+                arr[0][k] = adj[i][j];
+                arr[1][k] = i; 
+                arr[2][k] = j; 
+                k++;
+            }
+        }
+        n++;
+    }
+
+    cout<<endl;
+    printArray(arr,k-1);
+    cout<<endl;
+
+    // sort the edges in increasing order of weight
+    sort(arr ,k-1);
+    cout<<endl;
+    printArray(arr,k-1);
+    cout<<endl;
+
+    int i=0;
+    while(e<v-1){
+        if(check[arr[1][i]] == false || check[arr[2][i]] == false){
+            cout<<"edge : "<<arr[1][i]<<arr[2][i]<<" weight = "<<arr[0][i]<<endl;
+            check[arr[1][i]] = true;
+            check[arr[2][i]] = true;
+            cost += arr[0][i];
+            e++;
+        }
+        i++;
+    }
+
+    cout<<"\ncost = "<<cost<<endl;
+
+    return 0;
+}