mirror of https://github.com/ArduPilot/ardupilot
110 lines
2.8 KiB
C++
110 lines
2.8 KiB
C++
/*
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <stdint.h>
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#include "sorting.h"
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/*
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in-place insertion sort for small arrays of data. This is O(n) if
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already sorted and O(n^2) for worst case (elements are reversed)
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sort order is smallest first
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*/
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void insertion_sort_uint16(uint16_t *data, uint16_t n)
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{
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for (uint16_t i=1; i<n; i++) {
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uint16_t temp = data[i];
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int16_t j = i - 1;
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while (j >= 0 && data[j] > temp) {
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data[j+1] = data[j];
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j--;
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}
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data[j+1] = temp;
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}
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}
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/*
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remove duplicates from a sorted uint16_t array, returning the new
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count
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*/
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uint16_t remove_duplicates_uint16(uint16_t *data, uint16_t n)
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{
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uint16_t removed = 0;
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for (uint16_t i=1; i<n; i++) {
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if (data[i-(1+removed)] == data[i]) {
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removed++;
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} else if (removed != 0) {
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data[i-removed] = data[i];
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}
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}
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return n - removed;
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}
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/*
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bisection search on a sorted uint16_t array to find an element
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return true if found
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*/
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bool bisect_search_uint16(const uint16_t *data, uint16_t n, uint16_t value)
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{
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if (n == 0) {
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return false;
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}
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uint16_t low=0, high=n-1;
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while (low < high) {
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uint16_t mid = (low+high)/2;
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if (value < data[mid]) {
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high = mid;
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continue;
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}
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if (value > data[mid]) {
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low = mid+1;
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continue;
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}
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return true;
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}
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return data[low] == value;
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}
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/*
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remove elements in a 2nd sorted array from a sorted uint16_t array
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return the number of remaining elements
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*/
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uint16_t remove_list_uint16(uint16_t *data, uint16_t n, const uint16_t *rem, uint16_t n2)
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{
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uint16_t removed = 0;
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for (uint16_t i=0; i<n; i++) {
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if (bisect_search_uint16(rem, n2, data[i])) {
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removed++;
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} else if (removed != 0) {
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data[i-removed] = data[i];
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}
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}
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return n - removed;
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}
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/*
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return number of common elements between two sorted uint16_t lists
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*/
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uint16_t common_list_uint16(uint16_t *data, uint16_t n, const uint16_t *data2, uint16_t n2)
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{
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uint16_t common = 0;
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for (uint8_t i=0; i<n2; i++) {
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if (bisect_search_uint16(data, n, data2[i])) {
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common++;
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}
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}
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return common;
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}
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