pop&push

heap.cpp

@@ -0,0 +1,93 @@
+#include <iostream>
+#include <vector>
+#include <cmath>
+#include <fstream>
+
+
+class Heap {
+public:
+    int pop();
+    void push(int);
+    void print() const;
+    bool empty() const;
+private:
+    std::vector<int> data;
+
+    void dump(std::ofstream&, int) const;
+};
+
+void Heap::push(int h){
+    data.push_back(h);
+    for(int i = data.size(); i > 1; i /= 2){
+        if(data.at(i-1) < data.at(i/2-1)) std::swap(data[i-1], data[(i/2)-1]);
+        else break;
+    }
+}
+
+int Heap::pop(){
+    if (empty()) throw std::out_of_range("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
+    std::swap(data[0], data[data.size()-1]);
+    int garbage = data.back();
+    data.pop_back();
+    
+    int muj_index = 0;
+    while(true){
+        if(data.size() <= 2*muj_index+1) break;
+        int small_child_i;
+        if(data.size() > 2*muj_index+2 && data.at(2*muj_index+2) < data.at(2*muj_index+1))
+            small_child_i = 2*muj_index+2;
+        else small_child_i = 2*muj_index+1;
+
+        if(data.at(muj_index) > data.at(small_child_i)){
+            std::swap(data[muj_index], data[small_child_i]);
+            muj_index = small_child_i;
+        }else break;
+    }
+
+    return garbage;
+}
+
+bool Heap::empty() const{
+    return data.empty();
+}
+
+
+void Heap::dump(std::ofstream& ofs, int idx) const {
+    if (data.size() - 1 > 2 * idx) {
+        ofs << data[idx] << " -> " << data[idx * 2 + 1] << '\n';
+        dump(ofs, idx * 2 + 1);
+    }
+    if (data.size() - 1 > 2 * idx + 1) {
+        ofs << data[idx] << " -> " << data[idx * 2 + 1 + 1] << '\n';
+        dump(ofs, idx * 2 + 1 + 1);
+    }
+}
+
+void Heap::print() const {
+    std::ofstream ofs;
+    ofs.open("viz.dot");
+    ofs << "digraph Tree {\n";
+    dump(ofs, 0);
+    ofs << "}";
+
+    ofs.close();
+    system("cat viz.dot | dot -Tx11");
+}
+
+
+
+int main() {
+    Heap h;
+    std::vector<int> v = {1, 4, 9, 0, 7, 5, 8};
+
+    for (auto i : v) {
+        h.push(i);
+        h.print();
+    }
+
+    while (!h.empty()){
+        int i = h.pop();
+        h.print();
+    }
+    int aaaaaaaaaaaaaaa = h.pop();
+}