Generic 2D graph

1 files changed, 73 insertions, 0 deletions

diff --git a/graph.h b/graph.h
new file mode 100644
index 0000000..0b6c5c2
--- /dev/null
+++ b/graph.h
@@ -0,0 +1,73 @@
+typedef struct {
+	int	width;
+	int	height;
+	char**	e;
+	bool**	visited;
+} Graph2D;
+
+enum {
+	NORTH = 0, EAST, SOUTH, WEST, DIRECTIONS,
+};
+
+typedef struct {
+	int	x;
+	int	y;
+} Coordinates;
+
+bool
+valid(Graph2D* g, Coordinates c)
+{
+	return c.x >= 0 && c.x < g->width && c.y >= 0 && c.y < g->height;
+}
+
+/* Reads from the input until exhausted. Returns memory which must be
+freed by the caller. */
+Graph2D*
+ingest(FILE* in)
+{
+	char *t = getall(in);
+	char *s = t;
+
+	/* Two passes. One to count width and height.
+		Another to store to allocated memory. */
+	int height = 0, width = -1, i = 0;
+	while (s[i] != '\0') {
+		if (s[i] == '\n') {
+			if (width == -1) {
+				width = i + 1; 
+			}
+			height++;
+		}
+		i++;
+	}
+	char** buffer = calloc(height, sizeof(char*));
+	bool** visited = calloc(height, sizeof(bool*));
+
+	Graph2D* g = calloc(1, sizeof(Graph2D));
+	g->width = width;
+	g->height = height;
+	g->e = buffer;
+	g->visited = visited;
+	i = height;
+	while (i > 0) {
+		buffer[i-1] = calloc(width, sizeof(char));
+		visited[i-1] = calloc(width, sizeof(bool));
+		i--;
+	}
+
+	i = 0;
+	int j = 0;
+	while (i < height) {
+		if (j < width - 1) {
+			buffer[i][j] = *s;
+			j++;
+		} else {
+			i++;
+			j = 0;
+		}
+		s++;
+	}
+	
+	free(t);
+	return g;
+}