118 lines
3.5 KiB
C++
118 lines
3.5 KiB
C++
// 20:50
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// 22:31
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#include <iostream>
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const int N = 1000;
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class BigHeap {
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private:
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int *_internal_array;
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int len = 0;
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bool external = false;
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int get_left_child(int index) {
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return this->_internal_array[index * 2];
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}
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int get_right_child(int index) {
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return this->_internal_array[index * 2 + 1];
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}
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int get_parent(int index) {
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return this->_internal_array[index / 2];
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}
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void adjust_up(int index) {
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while (index > 1 && this->_internal_array[index] > this->get_parent(index)) {
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std::swap(this->_internal_array[index], this->_internal_array[index / 2]);
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index /= 2;
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}
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}
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void adjust_down(int index) {
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while (index * 2 <= this->len) {
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int target = index;
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if (this->_internal_array[target] < this->get_left_child(index)) // 如果左节点更大
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target = index * 2; // 左节点换上来
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if (index * 2 + 1 <= this->len && this->_internal_array[target] < this->get_right_child(index)) // 如果右节点更大
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target = index * 2 + 1; // 右节点换上来
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if (index == target)
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break;
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// 如果满足了当前节点比左右子节点大，就不用继续下沉了
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std::swap(this->_internal_array[index], this->_internal_array[target]);
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index = target;
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}
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}
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// 好像不太对，算了不用了，叶子节点直接判断就行了
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int get_last_non_leaf_index(int len) {
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int pow_of_2 = 1;
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int times = 0;
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while (pow_of_2 < len) {
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pow_of_2 *= 2; // 也可以写成 pow_of_2 <<= 2;
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times++;
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}
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return times;
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}
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public:
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BigHeap() { // 构造函数，在初始化时被调用
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this->_internal_array = new int[N];
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}
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BigHeap(int *external_array, int len) { // 也是构造函数，但是使用外部的数组初始化，数组要从1开始
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this->_internal_array = external_array;
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this->len = len;
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for (int i = this->len; i >= 1; i--) {
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adjust_down(i);
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}
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this->external = true;
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}
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~BigHeap() { // 析构函数，在对象被删除时被调用
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if (!this->external)
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delete this->_internal_array;
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}
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int get_length() {
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return this->len;
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}
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void insert(int num) {
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this->_internal_array[++this->len] = num;
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int index = this->len;
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adjust_up(index);
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}
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int pop() {
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int result = this->_internal_array[1];
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this->_internal_array[1] = this->_internal_array[this->len--];
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adjust_down(1);
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return result;
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}
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};
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int a[N];
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int len;
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int main() {
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std::cin >> len;
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for (int i = 1; i <= len; i++)
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std::cin >> a[i];
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BigHeap big_heap_internal;
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for (int i = 1; i <= len; i++) {
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big_heap_internal.insert(a[i]);
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}
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std::cout << "逐个插入后，逐个弹出输出的结果为：" << std::endl;
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while (big_heap_internal.get_length() > 0) {
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std::cout << big_heap_internal.pop() << " ";
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}
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std::cout << std::endl;
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BigHeap big_heap_external(a, len);
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std::cout << "一次性初始化后，逐个弹出输出的结果为：" << std::endl;
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while (big_heap_external.get_length() > 0) {
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std::cout << big_heap_external.pop() << " ";
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}
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std::cout << std::endl;
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return 0;
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} |