_datastructure_c_impl: Minimum spanning tree of graphs

#include <stdio.h> #include <stdlib.h> #include <string.h>typedef char vertextype[4];typedef Char infoptr;typedef int vrtype; #define INFINITY 10000//defines an infinitely large value # define MAXSIZE 50//MAX vertex number typedef Enum{dg,dn,ug,un} Types of graphkind;//graphs: the graph, the direction net, the non-direction graph and the non-direction network typedef struct{vrtype ADJ;//for the right graph, with 1 for the adjacent, 0 for the non-adjacent; for the weighted graph, the storage weights infoptr *info;// Information related to arcs or edges the type of the}arcnode,adjmatrix[maxsize][maxsize];//diagram defines typedef struct{vertextype vex[maxsize];//for storing vertices adjmatrix arc;//adjacency Matrix, storing the information of an edge or arc int vexnum,arcnum;//the number of vertices and edges (arcs) Graphkind The kind;//diagram's type}mgraph;//record the least-cost edge from the vertex collection u to v-u definition typedef Struct{vertextype Adjvex; Vrtype Lowcost;} Closeedge[maxsize];//finds Vertex v in the vertex vector, finds the ordinal returned in the vector, otherwise returns -1int Locatevertex (Mgraph N,vertextype v) {int i;for (i=0;i< N.vexnum;++i) if (strcmp (n.vex[i],v) ==0) return i;return-1;} Using adjacency matrix notation to create a nvoid creategraph (mgraph *n) {int I,j,k,w,infoflag,len;char s[maxsize]; Vertextype v1,v2;printf ("Please enter the number of vertices with the net N, ARC number, ARC information (yes: 1, no: 0):"), scanf ("%d,%d,%d",& (*n) .vexnum,& (*n). Arcnum, &infoflag);p rintf ("Please enter a value of%d vertices (<%d characters): \ n ", n->vexnum,maxsize); for (i=0;i<n->vexnum;++i)//save each vertex of the net scanf ("%s ", N->vex[i]); for (i=0;i<n- >vexnum;i++)//Initialize adjacency matrix for (j=0;j<n->vexnum;j++) {n->arc[i][j].adj=infinity; The information for the n->arc[i][j].info=null;//arc is initialized to an empty}printf ("Enter the arc-tail-arc-head weights for%d arcs (with spaces as intervals): \ n", n->arcnum); for (k=0;k<n-> arcnum;k++) {scanf ("%s%s%d", v1,v2,&w);//Input two vertex and arc weights I=locatevertex (*N,V1); J=locatevertex (*N,V2); N->arc[i][j].adj=w;if (Infoflag) {//If the arc contains other information printf ("Please enter information about arcs:"); gets (s); Len=strlen (s); if (len) {n->arc[i][ j].info= (char *) malloc ((len+1) *sizeof (char)); strcpy (n->arc[i][j].info,s);}} The type of n->kind=dn;//diagram is the}//destruction network nvoid destroygraph (mgraph *n) {int i,j;for (i=0;i<n->vexnum;i++)//release arc information for (j =0;j<n->vexnum;j++) if (n->arc[i][j].adj!=infinity)//If there is an arc if (n->arc[i][j].info!=null) {//If the arc has relevant information, Free space occupied by this information (N->arc[i][j].info); N->arc[i][j].info=null;} n->vexnum=0;//set the number of vertices of the net to 0n->arcnum=0;//the number of arcs in the net to 0}//void Displaygraph (mgraph N) {int i,j;printf ("Have a forward net with%d vertices% D arc, Vertex in order: ", N.VExnum,n.arcnum); for (i=0;i<n.vexnum;++i)//Output mesh vertex printf ("%s", N.vex[i]);p rintf ("\ n" \ n "\ n");//Output Net N's Arc printf (" Serial number i= "), for (i=0;i<n.vexnum;i++) printf ("%8d ", i);p rintf (" \ n "), for (i=0;i<n.vexnum;i++) {printf ("%8d ", I), and for (j =0;j<n.vexnum;j++) printf ("%8d", N.arc[i][j].adj);p rintf ("\ n"); }}//returns the ordinal of the minimum value of lowcost int mininum (Closeedge edge,mgraph G) {int i=0,j,k,min;while (!edge[i].lowcost) i++;min=edge[i]. lowcost;//the first value not to be 0 k=i;for (j=i+1;j<g.vexnum;j++) if (edge[j].lowcost>0&&edge[j].lowcost<min) {// Assigns the ordinal of the minimum value to kmin=edge[j].lowcost;k=j;} return k;} The minimum spanning tree tvoid Prim (mgraph g,vertextype u) {int I,j,k;closeedge Closedge;k=locatevertex (g,u) of constructing net G from the first u vertex is obtained by using the PRIMM algorithm; K for vertex u corresponding to the ordinal for (j=0;j<g.vexnum;j++) {//array initialization strcpy (closedge[j].adjvex,u); Closedge[j].lowcost=g.arc[k][j].adj;} closedge[k].lowcost=0;//Initial set u includes only vertex uprintf ("The edges of the smallest spanning tree of the non-net are: \ n"); for (i=1;i<g.vexnum;++i) {// Select the remaining g.vexnum-1 vertex k=mininum (closedge,g),//k is the ordinal of the next vertex adjacent to the vertex in U, printf ("(%s-%s) \ n", Closedge[k].adjvex,g.vex[k]); Edge Closedge of the output spanning tree[k].lowcost=0;//k Vertex incorporates U-set for (J=0;J&LT;G.VEXNUM;++J) if (g.arc[k][j].adj<closedge[j].lowcost) {// The new vertex is added to the U-set and the minimum edge is re-deposited into the array strcpy (Closedge[j].adjvex,g.vex[k]); Closedge[j].lowcost=g.arc[k][j].adj;}} void Main () {Mgraph n;printf ("Create a non-net: \ n"); Creategraph (&n);D isplaygraph (N); Prim (N, "A");D estroygraph (&n), System ("pause");

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_datastructure_c_impl: Minimum spanning tree of graphs