| /* |
| * This file is part of the MicroPython project, http://micropython.org/ |
| * |
| * The MIT License (MIT) |
| * |
| * Copyright (c) 2014 Damien P. George |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "py/objlist.h" |
| #include "py/runtime.h" |
| |
| #if MICROPY_PY_HEAPQ |
| |
| // the algorithm here is modelled on CPython's heapq.py |
| |
| static mp_obj_list_t *heapq_get_heap(mp_obj_t heap_in) { |
| if (!mp_obj_is_type(heap_in, &mp_type_list)) { |
| mp_raise_TypeError(MP_ERROR_TEXT("heap must be a list")); |
| } |
| return MP_OBJ_TO_PTR(heap_in); |
| } |
| |
| static void heapq_heap_siftdown(mp_obj_list_t *heap, mp_uint_t start_pos, mp_uint_t pos) { |
| mp_obj_t item = heap->items[pos]; |
| while (pos > start_pos) { |
| mp_uint_t parent_pos = (pos - 1) >> 1; |
| mp_obj_t parent = heap->items[parent_pos]; |
| if (mp_binary_op(MP_BINARY_OP_LESS, item, parent) == mp_const_true) { |
| heap->items[pos] = parent; |
| pos = parent_pos; |
| } else { |
| break; |
| } |
| } |
| heap->items[pos] = item; |
| } |
| |
| static void heapq_heap_siftup(mp_obj_list_t *heap, mp_uint_t pos) { |
| mp_uint_t start_pos = pos; |
| mp_uint_t end_pos = heap->len; |
| mp_obj_t item = heap->items[pos]; |
| for (mp_uint_t child_pos = 2 * pos + 1; child_pos < end_pos; child_pos = 2 * pos + 1) { |
| // choose right child if it's <= left child |
| if (child_pos + 1 < end_pos && mp_binary_op(MP_BINARY_OP_LESS, heap->items[child_pos], heap->items[child_pos + 1]) == mp_const_false) { |
| child_pos += 1; |
| } |
| // bubble up the smaller child |
| heap->items[pos] = heap->items[child_pos]; |
| pos = child_pos; |
| } |
| heap->items[pos] = item; |
| heapq_heap_siftdown(heap, start_pos, pos); |
| } |
| |
| static mp_obj_t mod_heapq_heappush(mp_obj_t heap_in, mp_obj_t item) { |
| mp_obj_list_t *heap = heapq_get_heap(heap_in); |
| mp_obj_list_append(heap_in, item); |
| heapq_heap_siftdown(heap, 0, heap->len - 1); |
| return mp_const_none; |
| } |
| static MP_DEFINE_CONST_FUN_OBJ_2(mod_heapq_heappush_obj, mod_heapq_heappush); |
| |
| static mp_obj_t mod_heapq_heappop(mp_obj_t heap_in) { |
| mp_obj_list_t *heap = heapq_get_heap(heap_in); |
| if (heap->len == 0) { |
| mp_raise_msg(&mp_type_IndexError, MP_ERROR_TEXT("empty heap")); |
| } |
| mp_obj_t item = heap->items[0]; |
| heap->len -= 1; |
| heap->items[0] = heap->items[heap->len]; |
| heap->items[heap->len] = MP_OBJ_NULL; // so we don't retain a pointer |
| if (heap->len) { |
| heapq_heap_siftup(heap, 0); |
| } |
| return item; |
| } |
| static MP_DEFINE_CONST_FUN_OBJ_1(mod_heapq_heappop_obj, mod_heapq_heappop); |
| |
| static mp_obj_t mod_heapq_heapify(mp_obj_t heap_in) { |
| mp_obj_list_t *heap = heapq_get_heap(heap_in); |
| for (mp_uint_t i = heap->len / 2; i > 0;) { |
| heapq_heap_siftup(heap, --i); |
| } |
| return mp_const_none; |
| } |
| static MP_DEFINE_CONST_FUN_OBJ_1(mod_heapq_heapify_obj, mod_heapq_heapify); |
| |
| #if !MICROPY_ENABLE_DYNRUNTIME |
| static const mp_rom_map_elem_t mp_module_heapq_globals_table[] = { |
| { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_heapq) }, |
| { MP_ROM_QSTR(MP_QSTR_heappush), MP_ROM_PTR(&mod_heapq_heappush_obj) }, |
| { MP_ROM_QSTR(MP_QSTR_heappop), MP_ROM_PTR(&mod_heapq_heappop_obj) }, |
| { MP_ROM_QSTR(MP_QSTR_heapify), MP_ROM_PTR(&mod_heapq_heapify_obj) }, |
| }; |
| |
| static MP_DEFINE_CONST_DICT(mp_module_heapq_globals, mp_module_heapq_globals_table); |
| |
| const mp_obj_module_t mp_module_heapq = { |
| .base = { &mp_type_module }, |
| .globals = (mp_obj_dict_t *)&mp_module_heapq_globals, |
| }; |
| |
| MP_REGISTER_EXTENSIBLE_MODULE(MP_QSTR_heapq, mp_module_heapq); |
| #endif |
| |
| #endif // MICROPY_PY_HEAPQ |