1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
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
graph_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*
graph_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;
}
void
graph_free(Graph2D* g)
{
for (int i = 0; i < g->height; i++) {
free(g->e[i]);
free(g->visited[i]);
}
free(g->e);
free(g->visited);
free(g);
}
|
