92 lines
2.8 KiB
JavaScript
92 lines
2.8 KiB
JavaScript
|
|
/*
|
|
* Licensed to the Apache Software Foundation (ASF) under one
|
|
* or more contributor license agreements. See the NOTICE file
|
|
* distributed with this work for additional information
|
|
* regarding copyright ownership. The ASF licenses this file
|
|
* to you 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.
|
|
*/
|
|
|
|
|
|
/**
|
|
* AUTO-GENERATED FILE. DO NOT MODIFY.
|
|
*/
|
|
|
|
/*
|
|
* Licensed to the Apache Software Foundation (ASF) under one
|
|
* or more contributor license agreements. See the NOTICE file
|
|
* distributed with this work for additional information
|
|
* regarding copyright ownership. The ASF licenses this file
|
|
* to you 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.
|
|
*/
|
|
function defaultCompareFunc(a, b) {
|
|
return a - b;
|
|
}
|
|
function swapElement(arr, idx0, idx1) {
|
|
var tmp = arr[idx0];
|
|
arr[idx0] = arr[idx1];
|
|
arr[idx1] = tmp;
|
|
}
|
|
function select(arr, left, right, nth, compareFunc) {
|
|
var pivotIdx = left;
|
|
var pivotValue;
|
|
while (right > left) {
|
|
pivotIdx = Math.round((right + left) / 2);
|
|
pivotValue = arr[pivotIdx];
|
|
// Swap pivot to the end
|
|
swapElement(arr, pivotIdx, right);
|
|
pivotIdx = left;
|
|
for (var i = left; i <= right - 1; i++) {
|
|
if (compareFunc(pivotValue, arr[i]) >= 0) {
|
|
swapElement(arr, i, pivotIdx);
|
|
pivotIdx++;
|
|
}
|
|
}
|
|
swapElement(arr, right, pivotIdx);
|
|
if (pivotIdx === nth) {
|
|
return pivotIdx;
|
|
} else if (pivotIdx < nth) {
|
|
left = pivotIdx + 1;
|
|
} else {
|
|
right = pivotIdx - 1;
|
|
}
|
|
}
|
|
// Left == right
|
|
return left;
|
|
}
|
|
function quickSelect(arr, left, right, nth, compareFunc) {
|
|
if (arguments.length <= 3) {
|
|
nth = left;
|
|
if (arguments.length === 2) {
|
|
compareFunc = defaultCompareFunc;
|
|
} else {
|
|
compareFunc = right;
|
|
}
|
|
left = 0;
|
|
right = arr.length - 1;
|
|
}
|
|
return select(arr, left, right, nth, compareFunc);
|
|
}
|
|
export default quickSelect; |