如何做网站背景,做网站公司青浦,seo学习,wordpress 浏览人数目录 1 单例模式2 工厂方法模式3 抽象工厂模式4参考 1 单例模式
题目链接为#xff1a;小明的购物车
C代码如下#xff0c;
#include iostream
#include string
#include vectorusing namespace std;class ShoppingCart {
public:static Shopping… 目录 1 单例模式2 工厂方法模式3 抽象工厂模式4参考 1 单例模式
题目链接为小明的购物车
C代码如下
#include iostream
#include string
#include vectorusing namespace std;class ShoppingCart {
public:static ShoppingCart get_instance() {static ShoppingCart instance ShoppingCart(); //静态变量类的所有对象共用一个return instance;}vectorstring get_goods() { return goods;}vectorint get_cnt() {return cnt;}void show() {int n goods.size();for (int i 0; i n; i) {cout goods[i] cnt[i] endl;}return;}private:ShoppingCart () {} //构造函数私有化防止外部直接实例化类的对象vectorstring goods; vectorint cnt;
};int main() {ShoppingCart shopping_cart ShoppingCart::get_instance();string a;int b;while (cin a b) {shopping_cart.get_goods().emplace_back(a);shopping_cart.get_cnt().emplace_back(b);}shopping_cart.show();return 0;
}注意要点
构造函数私有化防止外部直接实例化ShoppingCart类的对象。静态变量instance只会被创建一次故ShoppingCart类的所有对象共用一个instance。又因为变量instance的类型为ShoppingCart故该类只会存在一个实例化对象。
2 工厂方法模式
题目链接积木工厂
C代码如下
#include iostream
#include vectorusing namespace std;class Block {
public:virtual void produce() 0;
};class CircleBlock : public Block {void produce() override {cout Circle Block endl;}
};class SquareBlock : public Block {
public:void produce() override {cout Square Block endl;}
};class BlockFactory {
public:virtual Block* createBlock() 0;
};class CircleBlockFactory : public BlockFactory {
public:Block* createBlock() override {return new CircleBlock();}
};class SquareBlockFactory : public BlockFactory {
public:Block* createBlock() override {return new SquareBlock();}
};class BlockFactorySystem {
private:vectorBlock* blocks;public:void produceBlocks(BlockFactory* factory, int quantity) {for (int i 0; i quantity; i) {Block* block factory-createBlock();blocks.emplace_back(block);block-produce();}}const vectorBlock* getBlocks() const {return blocks;} ~BlockFactorySystem() {for (Block* block : blocks) {delete block;}}
};int main() {BlockFactorySystem factorySystem;int productionCount;cin productionCount;for (int i 0; i productionCount; i) {string blockType;int quantity;cin blockType quantity;if (blockType Circle) {factorySystem.produceBlocks(new CircleBlockFactory(), quantity);} else if (blockType Square) {factorySystem.produceBlocks(new SquareBlockFactory(), quantity);}}return 0;
}3 抽象工厂模式
题目链接家具工厂
C代码如下
#include iostream
#include stringusing namespace std;class Chair {
public:virtual void showInfo() 0;
};class ModernChair : public Chair {
public:void showInfo() override {cout modern chair endl;}
};class ClassicalChair : public Chair {
public:void showInfo() override {cout classical chair endl;}
};class Sofa {
public:virtual void displayInfo() 0;
};class ModernSofa : public Sofa {
public:void displayInfo() override {cout modern sofa endl;}
};class ClassicalSofa : public Sofa {
public:void displayInfo() override {cout classical sofa endl;}
};class FurnitureFactory {
public:virtual Chair* createChair() 0;virtual Sofa* createSofa() 0;
};class ModernFurnitureFactory : public FurnitureFactory {
public:Chair* createChair() override {return new ModernChair();}Sofa* createSofa() override {return new ModernSofa();}
};class ClassicalFurnitureFactory : public FurnitureFactory {
public:Chair* createChair() override {return new ClassicalChair();}Sofa* createSofa() override {return new ClassicalSofa();}
};int main() {int N;cin N;for (int i 0; i N; i) {string furnitureType;cin furnitureType;FurnitureFactory* factory nullptr;if (furnitureType modern) {factory new ModernFurnitureFactory(); } else if (furnitureType classical) {factory new ClassicalFurnitureFactory();}Chair* chair factory-createChair();Sofa* sofa factory-createSofa();chair-showInfo();sofa-displayInfo();delete chair;delete sofa;delete factory;}return 0;
}4
参考
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