【C语言】用C语言实现组合模式 - 谷动谷力

#include <stdlib.h>
enum type{ LEAF = 1, BRANCH,};// 定义组件接口typedef struct Component { int value; int type; void (*operation)(struct Component *);} Component;
// 定义叶子节点typedef struct Leaf { Component base;} Leaf;
void leaf_operation(Component *component) { printf("Leaf: %d\n", component->value);}
Leaf* leaf_create(int value) { Leaf *leaf = (Leaf*)malloc(sizeof(Leaf)); leaf->base.value = value; leaf->base.type = LEAF; leaf->base.operation = leaf_operation; return leaf;}
// 定义组合节点typedef struct Composite { Component base; Component **children; int num_children;} Composite;
#define offsetof(s, m) ((size_t)&(((s *)0)->m))#define container_of(ptr, type, member) \ ((type *)((char *)(ptr) - offsetof(type, member)))
void composite_operation(Component *component) { Composite *composite = (Composite*)component; printf("Composite: %d\n", component->value);
for (int i = 0; i < composite->num_children; i++) { composite->children[i]->operation(composite->children[i]); }}
Composite* composite_create(int value, int num_children) { Composite *composite = (Composite*)malloc(sizeof(Composite)); composite->base.value = value; composite->base.type = BRANCH; composite->base.operation = composite_operation; composite->num_children = num_children; composite->children = (Component**)malloc(sizeof(Component*) * num_children); for (int i = 0; i < num_children; i++) { composite->children[i] = NULL; } return composite;}
void composite_add_child(Composite *composite, Component *child, int index) { if (index < 0 || index >= composite->num_children) { printf("Invalid index %d\n", index); return; } composite->children[index] = child;}
void composite_remove_child(Composite *composite, int index) { if (index < 0 || index >= composite->num_children) { printf("Invalid index %d\n", index); return; } composite->children[index] = NULL;}
void composite_free_unit(Composite *composite) { if (!composite) return;
if (composite->base.type == LEAF) return;
for (int i = 0; i < composite->num_children; i++) { if (composite->children[i]) { composite_free_unit((struct Composite*)container_of(composite->children[i], struct Composite, base)); printf("free children[%d], value: %d\n", i, composite->children[i]->value); free(composite->children[i]); } }
if (composite->children) { free(composite->children); }}
void composite_free(Composite *composite) { composite_free_unit(composite); if (composite) { free(composite); }}int main() { printf("create root and leaf\n"); // 创建根节点和叶子节点 Composite *root = composite_create(0, 3); Leaf *leaf1 = leaf_create(1); Leaf *leaf2 = leaf_create(2);
// 将叶子节点添加到根节点中 composite_add_child(root, &leaf1->base, 0); composite_add_child(root, &leaf2->base, 1);
// 创建子节点并将其添加到根节点中 Composite *subtree = composite_create(3, 2); Leaf *leaf3 = leaf_create(4); Leaf *leaf4 = leaf_create(5); composite_add_child(subtree, &leaf3->base, 0); composite_add_child(subtree, &leaf4->base, 1); composite_add_child(root, &subtree->base, 2);
// 执行操作 root->base.operation(&root->base);
printf("free root and leaf\n"); // 释放内存 composite_free(root);
return 0;}

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