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MINHEAP.CPP
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MINHEAP.CPP
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#include <iostream>
#include <cstdint>
using namespace std;
template <typename T>
class min_heap {
T** arr;
uint32_t capacity;
uint32_t size;
public:
void swap(T** x, T** y) {
T* temp = *x;
*x = *y;
*y = temp;
}
min_heap(uint32_t cap) {
size = 0;
capacity = cap;
arr = new T*[cap];
}
void solve(uint32_t i) {
uint32_t l = left(i);
uint32_t r = right(i);
uint32_t smallest = i;
if (l < size && greater(arr[i], arr[l])) smallest = l;
if (r < size && greater(arr[smallest], arr[r])) smallest = r;
if (smallest != i) {
swap(&arr[i], &arr[smallest]);
solve(smallest);
}
}
uint32_t parent(uint32_t i) { return (i - 1) / 2; }
uint32_t left(uint32_t i) { return (i<<1) + 1; }
uint32_t right (uint32_t i) { return (i<<1) + 2; }
T* poll() {
if (size <= 0) return nullptr;
if (size == 1) {
size--;
return arr[0];
}
T* root = arr[0];
arr[0] = arr[size - 1];
size--;
solve(0);
return root;
}
T* peek() { return arr[0]; };
bool greater(T* x, T* y) { // greater?
return *x > *y;
}
bool insert(T* val) {
if (size == capacity) return false;
size++;
uint32_t i = size - 1;
arr[i] = val;
while (i != 0 && greater(arr[parent(i)], arr[i])) {
swap(&arr[i], &arr[parent(i)]);
i = parent(i);
}
return true;
}
};
int main() {
min_heap<uint32_t> heap(1024);
for (uint32_t i = 0; i < 621; i++) heap.insert(new uint32_t ((835 * i + 22) % 621) );
while (true) {
uint32_t* x = heap.poll();
if (x == nullptr) break;
cout << *x << endl;
}
}