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392d65ba MR |
1 | #include <stdlib.h> |
2 | #include "stack.h" | |
3 | ||
4 | #define INIT_SIZE 100 | |
5 | ||
6 | struct _Stack { | |
7 | int size; | |
8 | void** elems; | |
9 | StackFreeFunc free; | |
10 | }; | |
11 | ||
12 | static void free_elem(Stack* stack) { | |
13 | if (stack->free) { | |
14 | for (int i = 0; i < stack->size; i++) | |
15 | stack->free(stack->elems[i]); | |
16 | } | |
17 | free(stack->elems); | |
18 | } | |
19 | ||
20 | static Stack* stack_new_common() { | |
21 | Stack* s = malloc(sizeof(Stack)); | |
22 | s->elems = malloc(sizeof(void*) * INIT_SIZE); | |
23 | s->size = 0; | |
24 | s->free = NULL; | |
25 | return s; | |
26 | } | |
27 | ||
28 | Stack* stack_new() { | |
29 | return stack_new_common(); | |
30 | } | |
31 | ||
32 | Stack* stack_new_full(StackFreeFunc free) { | |
33 | Stack* s = stack_new_common(); | |
34 | s->free = free; | |
35 | return s; | |
36 | } | |
37 | ||
38 | void stack_destroy(Stack* stack) { | |
39 | free_elem(stack); | |
40 | free(stack); | |
41 | } | |
42 | ||
43 | void* stack_pop(Stack* stack) { | |
44 | if (stack_empty(stack)) | |
45 | return NULL; | |
46 | stack->size -= 1; | |
47 | void* elem = stack->elems[stack->size]; | |
48 | stack->elems[stack->size] = NULL; | |
49 | ||
50 | return elem; | |
51 | } | |
52 | ||
53 | void stack_push(Stack* stack, void* elem) { | |
54 | if (stack == NULL) | |
55 | return; | |
56 | ||
57 | stack->size += 1; | |
58 | if (stack->size == INIT_SIZE) { | |
59 | stack->elems = realloc(stack->elems, (INIT_SIZE + stack->size) * sizeof(void*)); | |
60 | } | |
61 | ||
62 | stack->elems[stack->size - 1] = elem; | |
63 | } | |
64 | ||
65 | void* stack_peek(Stack* stack) { | |
66 | if (stack_empty(stack)) | |
67 | return NULL; | |
68 | return stack->elems[stack->size - 1]; | |
69 | } | |
70 | ||
71 | bool stack_empty(Stack* stack) { | |
72 | return (stack == NULL || stack->size == 0); | |
73 | } | |
74 | ||
75 | void stack_clear(Stack* stack) { | |
76 | if (stack == NULL) | |
77 | return; | |
78 | ||
79 | free_elem(stack); | |
80 | stack->size = 0; | |
81 | } | |
82 | ||
83 | int stack_size(Stack* stack) { | |
84 | if (stack_empty(stack)) | |
85 | return 0; | |
86 | return stack->size; | |
87 | } | |
88 | ||
89 | /* | |
90 | typedef struct _Stack { | |
91 | void** elems; | |
92 | int size; | |
93 | StackFreeFunc free; | |
94 | } Stack; | |
95 | ||
96 | static void free_elem(Stack* stack) { | |
97 | if (stack->free) { | |
98 | for (int i = 0; i < stack->size; i++) | |
99 | stack->free(stack->elems[i]); | |
100 | } | |
101 | free(stack->elems); | |
102 | } | |
103 | ||
104 | Stack* stack_new() { | |
105 | Stack* s = malloc(sizeof(Stack)); | |
106 | s->size = 0; | |
107 | s->elems = NULL; | |
108 | s->free = NULL; | |
109 | return s; | |
110 | } | |
111 | ||
112 | Stack* stack_new_full(StackFreeFunc free) { | |
113 | Stack* s = malloc(sizeof(Stack)); | |
114 | s->size = 0; | |
115 | s->elems = NULL; | |
116 | s->free = free; | |
117 | return s; | |
118 | } | |
119 | ||
120 | void stack_destroy(Stack* stack) { | |
121 | free_elem(stack); | |
122 | free(stack); | |
123 | } | |
124 | ||
125 | void* stack_pop(Stack* stack) { | |
126 | if (stack_empty(stack)) | |
127 | return NULL; | |
128 | stack->size -= 1; | |
129 | void* elem = stack->elems[stack->size]; | |
130 | stack->elems[stack->size] = NULL; | |
131 | stack->elems = realloc(stack->elems, stack->size * sizeof(void*)); | |
132 | ||
133 | return elem; | |
134 | } | |
135 | ||
136 | void stack_push(Stack* stack, void* elem) { | |
137 | if (stack == NULL) | |
138 | return; | |
139 | ||
140 | stack->size += 1; | |
141 | stack->elems = realloc(stack->elems, stack->size * sizeof(void*)); | |
142 | stack->elems[stack->size - 1] = elem; | |
143 | } | |
144 | ||
145 | void* stack_peek(Stack* stack) { | |
146 | if (stack_empty(stack)) | |
147 | return NULL; | |
148 | return stack->elems[stack->size - 1]; | |
149 | } | |
150 | ||
151 | bool stack_empty(Stack* stack) { | |
152 | return (stack == NULL || stack->size == 0); | |
153 | } | |
154 | ||
155 | void stack_clear(Stack* stack) { | |
156 | if (stack == NULL) | |
157 | return; | |
158 | ||
159 | free_elem(stack); | |
160 | stack->size = 0; | |
161 | stack->elems = NULL; | |
162 | } | |
163 | ||
164 | int stack_size(Stack* stack) { | |
165 | if (stack_empty(stack)) | |
166 | return 0; | |
167 | return stack->size; | |
168 | } | |
169 | */ |