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author | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
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committer | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
commit | e0c6872cf40896c7be36b11dcc744620f10adf1d (patch) | |
tree | 60335e10d2f4354b0674ec22d7b53f0f8abee672 /support/graphbase/queen.w |
Initial commit
Diffstat (limited to 'support/graphbase/queen.w')
-rw-r--r-- | support/graphbase/queen.w | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/support/graphbase/queen.w b/support/graphbase/queen.w new file mode 100644 index 0000000000..43687e4dfa --- /dev/null +++ b/support/graphbase/queen.w @@ -0,0 +1,51 @@ +% This file is part of the Stanford GraphBase (c) Stanford University 1992 +\def\title{QUEEN} +@i boilerplate.w %<< legal stuff: PLEASE READ IT BEFORE MAKING ANY CHANGES! + +@* Introduction. This is a short demonstration of how to generate and +traverse graphs with the Stanford GraphBase. It creates a graph +with 12 vertices, representing the positions on a $3\times4$ rectangular +board; two positions are considered adjacent if you can get +from one to another by a queen move. Then it prints a description +of the vertices and their neighbors, on the standard output file. + +An ASCII file called \.{queen.gb} is also produced. Other programs +can make a copy of the queen graph by calling |restore_graph("queen.gb")|. +You may find it interesting to compare the output of |queen| with +the contents of \.{queen.gb}; the former is intended to be readable +by human beings, the latter by computers. + +@f Graph int /* |gb_graph| defines the |Graph| type and a few others */ +@f Vertex int +@f Arc int + +@p +#include "gb_graph.h" /* we use the |gb_graph| data structures */ +#include "gb_basic.h" /* we test the basic graph operations */ +#include "gb_save.h" /* and we save our results in ASCII format */ +@# +main() +{@+Graph *g,*gg,*ggg; + g=board(3,4,0,0,-1,0,0); /* a graph with rook moves */ + gg=board(3,4,0,0,-2,0,0); /* a graph with bishop moves */ + ggg=gunion(g,gg,0,0); /* a graph with queen moves */ + save_graph(ggg,"queen.gb"); /* generate an ASCII file for |ggg| */ + @<Print the vertices and edges of |ggg|@>; +} + +@ @<Print the vertices and edges of |ggg|@>= +if (ggg==NULL) printf("Something went wrong (panic code %d)!\n",panic_code); +else { + register Vertex *v; /* current vertex being visited */ + printf("Queen Moves on a 3x4 Board\n\n"); + printf(" The graph whose official name is\n%s\n", ggg->id); + printf(" has %d vertices and %d arcs:\n\n", ggg->n, ggg->m); + for (v=ggg->vertices; v<ggg->vertices+ggg->n; v++) { + register Arc *a; /* current arc from |v| */ + printf("%s\n", v->name); + for (a=v->arcs; a; a=a->next) + printf(" -> %s, length %d\n", a->tip->name, a->len); + } +} + +@* Index. |