@tensorflow/tfjs-core
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Hardware-accelerated JavaScript library for machine intelligence
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JavaScript
;
/**
* @license
* Copyright 2019 Google LLC. All Rights Reserved.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* =============================================================================
*/
Object.defineProperty(exports, "__esModule", { value: true });
/**
* Inserts a value into a sorted array. This method allows duplicate, meaning it
* allows inserting duplicate value, in which case, the element will be inserted
* at the lowest index of the value.
* @param arr The array to modify.
* @param element The element to insert.
* @param comparator Optional. If no comparator is specified, elements are
* compared using array_util.defaultComparator, which is suitable for Strings
* and Numbers in ascending arrays. If the array contains multiple instances of
* the target value, the left-most instance will be returned. To provide a
* comparator, it should take 2 arguments to compare and return a negative,
* zero, or a positive number.
*/
function binaryInsert(arr, element, comparator) {
var index = binarySearch(arr, element, comparator);
var insertionPoint = index < 0 ? -(index + 1) : index;
arr.splice(insertionPoint, 0, element);
}
exports.binaryInsert = binaryInsert;
/**
* Searches the array for the target using binary search, returns the index
* of the found element, or position to insert if element not found. If no
* comparator is specified, elements are compared using array_
* util.defaultComparator, which is suitable for Strings and Numbers in
* ascending arrays. If the array contains multiple instances of the target
* value, the left-most instance will be returned.
* @param arr The array to be searched in.
* @param target The target to be searched for.
* @param comparator Should take 2 arguments to compare and return a negative,
* zero, or a positive number.
* @return Lowest index of the target value if found, otherwise the insertion
* point where the target should be inserted, in the form of
* (-insertionPoint - 1).
*/
function binarySearch(arr, target, comparator) {
return binarySearch_(arr, target, comparator || defaultComparator);
}
exports.binarySearch = binarySearch;
/**
* Compares its two arguments for order.
* @param a The first element to be compared.
* @param b The second element to be compared.
* @return A negative number, zero, or a positive number as the first
* argument is less than, equal to, or greater than the second.
*/
function defaultComparator(a, b) {
return a > b ? 1 : a < b ? -1 : 0;
}
function binarySearch_(arr, target, comparator) {
var left = 0;
var right = arr.length;
var middle = 0;
var found = false;
while (left < right) {
middle = left + ((right - left) >>> 1);
var compareResult = comparator(target, arr[middle]);
if (compareResult > 0) {
left = middle + 1;
}
else {
right = middle;
// If compareResult is 0, the value is found. We record it is found,
// and then keep looking because there may be duplicate.
found = !compareResult;
}
}
return found ? left : -left - 1;
}
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