added kruskal algorithm in c

c/krushal.c

@@ -0,0 +1,123 @@
+
+#include<stdio.h>
+#define MAX 30
+
+typedef struct edge
+{
+    int u,v,w;
+}edge;
+
+typedef struct edgelist
+{
+    edge data[MAX];
+    int n;
+}edgelist;
+
+edgelist elist;
+
+int G[MAX][MAX],n;
+edgelist spanlist;
+
+void kruskal();
+int find(int belongs[],int vertexno);
+void union1(int belongs[],int c1,int c2);
+void sort();
+void print();
+
+void main()
+{
+    int i,j,total_cost;
+
+    printf("\nEnter number of vertices:");
+
+    scanf("%d",&n);
+
+    printf("\nEnter the adjacency matrix:\n");
+
+    for(i=0;i<n;i++)
+        for(j=0;j<n;j++)
+            scanf("%d",&G[i][j]);
+
+    kruskal();
+    print();
+}
+
+void kruskal()
+{
+    int belongs[MAX],i,j,cno1,cno2;
+    elist.n=0;
+
+    for(i=1;i<n;i++)
+        for(j=0;j<i;j++)
+        {
+            if(G[i][j]!=0)
+            {
+                elist.data[elist.n].u=i;
+                elist.data[elist.n].v=j;
+                elist.data[elist.n].w=G[i][j];
+                elist.n++;
+            }
+        }
+
+    sort();
+
+    for(i=0;i<n;i++)
+        belongs[i]=i;
+
+    spanlist.n=0;
+
+    for(i=0;i<elist.n;i++)
+    {
+        cno1=find(belongs,elist.data[i].u);
+        cno2=find(belongs,elist.data[i].v);
+
+        if(cno1!=cno2)
+        {
+            spanlist.data[spanlist.n]=elist.data[i];
+            spanlist.n=spanlist.n+1;
+            union1(belongs,cno1,cno2);
+        }
+    }
+}
+
+int find(int belongs[],int vertexno)
+{
+    return(belongs[vertexno]);
+}
+
+void union1(int belongs[],int c1,int c2)
+{
+    int i;
+
+    for(i=0;i<n;i++)
+        if(belongs[i]==c2)
+            belongs[i]=c1;
+}
+
+void sort()
+{
+    int i,j;
+    edge temp;
+
+    for(i=1;i<elist.n;i++)
+        for(j=0;j<elist.n-1;j++)
+            if(elist.data[j].w>elist.data[j+1].w)
+            {
+                temp=elist.data[j];
+                elist.data[j]=elist.data[j+1];
+                elist.data[j+1]=temp;
+            }
+}
+
+void print()
+{
+    int i,cost=0;
+
+    for(i=0;i<spanlist.n;i++)
+    {
+        printf("\n%d\t%d\t%d",spanlist.data[i].u,spanlist.data[i].v,spanlist.data[i].w);
+        cost=cost+spanlist.data[i].w;
+    }
+
+    printf("\n\nCost of the spanning tree=%d",cost);
+}