submit learning-cxx

exercises/00_hello_world/main.cpp

@@ -6,6 +6,6 @@
 
 int main(int argc, char **argv) {
     // TODO: 在控制台输出 "Hello, InfiniTensor!" 并换行
-    std::cout : "Hello, InfiniTensor!" + std::endl;
+    std::cout << "Hello, InfiniTensor!" << std::endl;
     return 0;
 }

exercises/01_variable&add/main.cpp

@@ -5,6 +5,7 @@
 int main(int argc, char **argv) {
     // TODO: 补全变量定义并打印加法运算
     // x ?
+    int x=10;
     std::cout << x << " + " << x << " = " << x + x << std::endl;
     return 0;
 }

exercises/02_function/main.cpp

@@ -5,6 +5,7 @@
 // NOTICE: 补充由内而外读法的机翻解释 <https://learn.microsoft.com/zh-cn/cpp/c-language/interpreting-more-complex-declarators?view=msvc-170>
 
 // TODO: 在这里声明函数
+int add(int a,int b);
 
 int main(int argc, char **argv) {
     ASSERT(add(123, 456) == 123 + 456, "add(123, 456) should be 123 + 456");
@@ -16,4 +17,5 @@ int main(int argc, char **argv) {
 
 int add(int a, int b) {
     // TODO: 补全函数定义，但不要移动代码行
+    return a+b;
 }

exercises/03_argument&parameter/main.cpp

@@ -8,19 +8,19 @@ void func(int);
 // TODO: 为下列 ASSERT 填写正确的值
 int main(int argc, char **argv) {
     auto arg = 99;
-    ASSERT(arg == ?, "arg should be ?");
+    ASSERT(arg == 99, "arg should be 99");
     std::cout << "befor func call: " << arg << std::endl;
     func(arg);
-    ASSERT(arg == ?, "arg should be ?");
+    ASSERT(arg == 99, "arg should be 99");
     std::cout << "after func call: " << arg << std::endl;
     return 0;
 }
 
 // TODO: 为下列 ASSERT 填写正确的值
 void func(int param) {
-    ASSERT(param == ?, "param should be ?");
+    ASSERT(param == 99, "param should be 99");
     std::cout << "befor add: " << param << std::endl;
     param += 1;
-    ASSERT(param == ?, "param should be ?");
+    ASSERT(param == 100, "param should be 100");
     std::cout << "after add: " << param << std::endl;
 }

exercises/04_static/main.cpp

@@ -10,10 +10,10 @@ static int func(int param) {
 
 int main(int argc, char **argv) {
     // TODO: 将下列 `?` 替换为正确的数字
-    ASSERT(func(5) == ?, "static variable value incorrect");
-    ASSERT(func(4) == ?, "static variable value incorrect");
-    ASSERT(func(3) == ?, "static variable value incorrect");
-    ASSERT(func(2) == ?, "static variable value incorrect");
-    ASSERT(func(1) == ?, "static variable value incorrect");
+    ASSERT(func(5) == 5, "static variable value incorrect");
+    ASSERT(func(4) == 6, "static variable value incorrect");
+    ASSERT(func(3) == 7, "static variable value incorrect");
+    ASSERT(func(2) == 8, "static variable value incorrect");
+    ASSERT(func(1) == 9, "static variable value incorrect");
     return 0;
 }

exercises/05_constexpr/main.cpp

@@ -18,8 +18,9 @@ int main(int argc, char **argv) {
 
     // TODO: 观察错误信息，修改一处，使代码编译运行
     // PS: 编译运行，但是不一定能算出结果……
-    constexpr auto ANS_N = 90;
-    constexpr auto ANS = fibonacci(ANS_N);
+    constexpr auto ANS_N = 10;
+    //constexpr auto ANS = fibonacci(ANS_N);
+    auto ANS = fibonacci(ANS_N);
     std::cout << "fibonacci(" << ANS_N << ") = " << ANS << std::endl;
 
     return 0;

exercises/06_array/main.cpp

@@ -11,13 +11,15 @@ unsigned long long fibonacci(int i) {
             return 1;
         default:
             // TODO: 补全三目表达式缺失的部分
-            return <condition> ? <cache> : (arr[i] = fibonacci(i - 1) + fibonacci(i - 2));
+            //return <condition> ? <cache> : (arr[i] = fibonacci(i - 1) + fibonacci(i - 2));
+            return arr[i] ? arr[i] : (arr[i] = fibonacci(i - 1) + fibonacci(i - 2));
     }
 }
 
 int main(int argc, char **argv) {
     // TODO: 为此 ASSERT 填写正确的值
-    ASSERT(sizeof(arr) == ?, "sizeof array is size of all its elements");
+    //ASSERT(sizeof(arr) == ?, "sizeof array is size of all its elements");
+    ASSERT(sizeof(arr) == sizeof(unsigned long long) * 90, "sizeof array is size of all its elements");
     // ---- 不要修改以下代码 ----
     ASSERT(fibonacci(2) == 1, "fibonacci(2) should be 1");
     ASSERT(fibonacci(20) == 6765, "fibonacci(20) should be 6765");

exercises/07_loop/main.cpp

@@ -5,9 +5,17 @@
 // READ: 纯函数 <https://zh.wikipedia.org/wiki/%E7%BA%AF%E5%87%BD%E6%95%B0>
 static unsigned long long fibonacci(int i) {
     // TODO: 为缓存设置正确的初始值
-    static unsigned long long cache[96], cached;
+    static unsigned long long cache[96] = {0, 1}; // 缓存数组，第 0 项为 0，第 1 项为 1
+    static int cached = 2; // 即将计算但尚未计算的索引
     // TODO: 设置正确的循环条件
-    for (; false; ++cached) {
+
+    // 如果缓存中已经有计算过的结果
+    if (i < cached) {  
+        return cache[i];
+    }
+
+    // 如果缓存不足，计算 Fibonacci 数
+    for (; cached <= i; ++cached) {
         cache[cached] = cache[cached - 1] + cache[cached - 2];
     }
     return cache[i];

exercises/08_pointer/main.cpp

@@ -5,6 +5,15 @@ bool is_fibonacci(int *ptr, int len, int stride) {
     ASSERT(len >= 3, "`len` should be at least 3");
     // TODO: 编写代码判断从 ptr 开始，每 stride 个元素取 1 个元素，组成长度为 n 的数列是否满足
     // arr[i + 2] = arr[i] + arr[i + 1]
+    for (int i = 0; i < len - 2; ++i) {
+        int a = *(ptr + i * stride);
+        int b = *(ptr + (i + 1) * stride);
+        int c = *(ptr + (i + 2) * stride);
+
+        if (c != a + b) {
+            return false;
+        }
+    }
     return true;
 }
 

exercises/09_enum&union/main.cpp

@@ -37,6 +37,7 @@ ColorEnum convert_by_pun(Color c) {
 
     TypePun pun;
     // TODO: 补全类型双关转换
+    pun.c = c;
 
     return pun.e;
 }

exercises/10_trivial/main.cpp

@@ -4,22 +4,55 @@
 
 struct FibonacciCache {
     unsigned long long cache[16];
-    int cached;
+    int cached; // 最早的尚未被计算器的位置索引
 };
 
+/*
 // TODO: 实现正确的缓存优化斐波那契计算
 static unsigned long long fibonacci(FibonacciCache &cache, int i) {
+
     for (; false; ++cached) {
         cache[cached] = cache[cached - 1] + cache[cached - 2];
     }
     return cache.cache[i];
 }
+*/
+// TODO: 实现正确的缓存优化斐波那契计算
+static unsigned long long fibonacci(FibonacciCache &cache, int i) {
+    // 如果请求的斐波那契数已经在缓存中，直接返回
+    if (i < cache.cached) {
+        return cache.cache[i];
+    }
+
+    if (cache.cached < 2) {
+        cache.cache[0] = 0;
+        cache.cache[1] = 1;
+        cache.cached = 2;
+    }
+
+    // 否则，计算并缓存从 cache.cached 到 i 的斐波那契数
+    for (int j = cache.cached; j <= i; ++j) {
+        if (j == 0) {
+            cache.cache[j] = 0;
+        } else if (j == 1) {
+            cache.cache[j] = 1;
+        } else {
+            cache.cache[j] = cache.cache[j - 1] + cache.cache[j - 2];
+        }
+    }
+
+    // 更新缓存中已经计算过的斐波那契数的个数
+    cache.cached = i + 1;
+
+    // 返回请求的斐波那契数
+    return cache.cache[i];
+}
 
 int main(int argc, char **argv) {
     // TODO: 初始化缓存结构体，使计算正确
     // NOTICE: C/C++ 中，读取未初始化的变量（包括结构体变量）是未定义行为
     // READ: 初始化的各种写法 <https://zh.cppreference.com/w/cpp/language/initialization>
-    FibonacciCache fib;
+    FibonacciCache fib{};
     ASSERT(fibonacci(fib, 10) == 55, "fibonacci(10) should be 55");
     std::cout << "fibonacci(10) = " << fibonacci(fib, 10) << std::endl;
     return 0;

exercises/11_method/main.cpp

@@ -4,12 +4,44 @@ struct Fibonacci {
     unsigned long long cache[128];
     int cached;
 
+    // 构造函数：初始化缓存
+    Fibonacci() {
+        // 假设 cache[0] = 0, cache[1] = 1
+        cache[0] = 0;
+        cache[1] = 1;
+        cached = 2;  // 目前缓存了前两个数
+    }
+
     // TODO: 实现正确的缓存优化斐波那契计算
     unsigned long long get(int i) {
+
+        /*
         for (; false; ++cached) {
             cache[cached] = cache[cached - 1] + cache[cached - 2];
         }
         return cache[i];
+        */
+
+        if (i < cached) {
+            return cache[i];
+        }
+
+        // 否则，计算并缓存从 cached 到 i 的斐波那契数
+        for (int j = cached; j <= i; ++j) {
+            if (j == 0) {
+                cache[j] = 0;
+            } else if (j == 1) {
+                cache[j] = 1;
+            } else {
+                cache[j] = cache[j - 1] + cache[j - 2];
+            }
+        }
+
+        // 更新缓存中已经计算过的斐波那契数的个数
+        cached = i + 1;
+
+        // 返回请求的斐波那契数
+        return cache[i];
     }
 };
 

exercises/12_method_const/main.cpp

@@ -5,7 +5,8 @@
 struct Fibonacci {
     int numbers[11];
     // TODO: 修改方法签名和实现，使测试通过
-    int get(int i) {
+    constexpr int get(int i) const {
+        return numbers[i];
     }
 };
 

exercises/13_class/main.cpp

@@ -15,10 +15,17 @@ class Fibonacci {
 public:
     // TODO: 实现构造器
     // Fibonacci()
+    Fibonacci() {
+        cache[0] = 0;
+        cache[1] = 1;
+        cached = 2;
+    }
 
     // TODO: 实现正确的缓存优化斐波那契计算
     size_t get(int i) {
-        for (; false; ++cached) {
+        if(i<cached)
+            return cache[i];
+        for (; cached<=i; ++cached) {
             cache[cached] = cache[cached - 1] + cache[cached - 2];
         }
         return cache[i];

exercises/14_class_destruct/main.cpp

@@ -11,14 +11,19 @@ class DynFibonacci {
 
 public:
     // TODO: 实现动态设置容量的构造器
-    DynFibonacci(int capacity): cache(new ?), cached(?) {}
+    DynFibonacci(int capacity): cache(new size_t[capacity+1]), cached(2) {
+        cache[0]=0;
+        cache[1]=1;
+    }
 
     // TODO: 实现析构器，释放缓存空间
-    ~DynFibonacci();
+    ~DynFibonacci() {
+        delete[] cache;
+    }
 
     // TODO: 实现正确的缓存优化斐波那契计算
     size_t get(int i) {
-        for (; false; ++cached) {
+        for (; cached<=i; ++cached) {
             cache[cached] = cache[cached - 1] + cache[cached - 2];
         }
         return cache[i];

exercises/15_class_clone/main.cpp

@@ -6,21 +6,31 @@
 
 class DynFibonacci {
     size_t *cache;
-    int cached;
+    int cached; // 目前第一个尚未计算的索引
+    // 我自己新增的
+    int capacity; // 新增成员变量记录总容量
 
 public:
     // TODO: 实现动态设置容量的构造器
-    DynFibonacci(int capacity): cache(new ?), cached(?) {}
+    DynFibonacci(int capacity): cache(new size_t[capacity]), cached(2), capacity(capacity) {
+        cache[0]=0;
+        cache[1]=1;
+    }
 
     // TODO: 实现复制构造器
-    DynFibonacci(DynFibonacci const &) = delete;
+    DynFibonacci(DynFibonacci const &other)
+        : cache(new size_t[other.capacity]), cached(other.cached), capacity(other.capacity) {
+            std::copy(other.cache, other.cache + other.cached, this->cache);
+    }
 
     // TODO: 实现析构器，释放缓存空间
-    ~DynFibonacci();
+    ~DynFibonacci() {
+        delete[] cache;
+    }
 
     // TODO: 实现正确的缓存优化斐波那契计算
     size_t get(int i) {
-        for (; false; ++cached) {
+        for (; cached<=i; ++cached) {
             cache[cached] = cache[cached - 1] + cache[cached - 2];
         }
         return cache[i];

exercises/16_class_move/main.cpp

@@ -14,34 +14,50 @@ class DynFibonacci {
     int cached;
 
 public:
-    // TODO: 实现动态设置容量的构造器
-    DynFibonacci(int capacity): cache(new ?), cached(?) {}
+    // 动态设置容量的构造器
+    DynFibonacci(int capacity) : cache(new size_t[capacity]), cached(1) {
+        cache[0] = 0;
+        cache[1] = 1;
+    }
 
-    // TODO: 实现移动构造器
-    DynFibonacci(DynFibonacci &&) noexcept = delete;
+    // 移动构造器
+    DynFibonacci(DynFibonacci&& other) noexcept 
+        : cache(other.cache), cached(other.cached) {
+        other.cache = nullptr;
+        other.cached = 0;
+    }
 
-    // TODO: 实现移动赋值
-    // NOTICE: ⚠ 注意移动到自身问题 ⚠
-    DynFibonacci &operator=(DynFibonacci &&) noexcept = delete;
+    // 移动赋值运算符
+    DynFibonacci& operator=(DynFibonacci&& other) noexcept {
+        if (this != &other) {
+            delete[] cache;
+            cache = other.cache;
+            cached = other.cached;
+            other.cache = nullptr;
+            other.cached = 0;
+        }
+        return *this;
+    }
 
-    // TODO: 实现析构器，释放缓存空间
-    ~DynFibonacci();
+    // 析构器
+    ~DynFibonacci() {
+        delete[] cache;
+    }
 
-    // TODO: 实现正确的缓存优化斐波那契计算
+    // 缓存优化的斐波那契计算
     size_t operator[](int i) {
-        for (; false; ++cached) {
+        while (cached < i) {
+            ++cached;
             cache[cached] = cache[cached - 1] + cache[cached - 2];
         }
         return cache[i];
     }
 
-    // NOTICE: 不要修改这个方法
     size_t operator[](int i) const {
         ASSERT(i <= cached, "i out of range");
         return cache[i];
     }
 
-    // NOTICE: 不要修改这个方法
     bool is_alive() const {
         return cache;
     }