added prims.cpp in graph

Author: samarth-asthana

Graph/prims.cpp

@@ -0,0 +1,73 @@
+#include <iostream>
+#define I INT_MAX
+using namespace std; 
+int cost[][8]= 
+ {{I,I,I,I,I,I,I,I}, 
+ {I,I,25,I,I,I,5,I}, 
+ {I,25,I,12,I,I,I,10}, 
+ {I,I,12,I,8,I,I,I}, 
+ {I,I,I,8,I,16,I,14}, 
+ {I,I,I,I,16,I,20,18}, 
+ {I,5,I,I,I,20,I,I}, 
+ {I,I,10,I,14,18,I,I}}; 
+int near[8]={I,I,I,I,I,I,I,I}; 
+int t[2][6]; 
+int main() 
+{ 
+ int i,j,k,u,v,n=7,min=I; 
+ 
+ for(i=1;i<=n;i++) 
+ { 
+ for(j=i;j<=n;j++) 
+ { 
+ if(cost[i][j]<min) 
+ { 
+ min=cost[i][j]; 
+ u=i; 
+ v=j; 
+ } 
+ } 
+ } 
+ t[0][0]=u;t[1][0]=v; 
+ near[u]=near[v]=0; 
+ 
+ for(i=1;i<=n;i++) 
+ { 
+ if(near[i]!=0) 
+ { 
+ if(cost[i][u]<cost[i][v]) 
+ near[i]=u; 
+ else
+ near[i]=v; 
+ } 
+ } 
+ 
+ for(i=1;i<n-1;i++) 
+ { 
+ min=I; 
+ for(j=1;j<=n;j++) 
+ { 
+ if(near[j]!=0 && cost[j][near[j]]<min) 
+ { 
+ k=j; 
+ min=cost[j][near[j]]; 
+ } 
+ } 
+ t[0][i]=k; 
+ t[1][i]=near[k]; 
+ near[k]=0; 
+ 
+ for(j=1;j<=n;j++) 
+ { 
+ if(near[j]!=0 && cost[j][k]<cost[j][near[j]]) 
+ near[j]=k; 
+ } 
+ 
+ } 
+ 
+ for(i=0;i<n-1;i++) 
+ { 
+ cout<<"("<<t[0][i]<<","<<t[1][i]<<")"<<endl; 
+ } 
+ 
+}