39 lines
957 B
JavaScript
39 lines
957 B
JavaScript
const countingSort = array => {
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if (array.length <= 1) return
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const max = findMaxValue(array)
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const counts = new Array(max + 1)
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// 计算每个元素的个数，放入到counts桶中
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// counts下标是元素，值是元素个数
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array.forEach(element => {
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if (!counts[element]) {
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counts[element] = 0
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}
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counts[element]++
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})
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// counts下标是元素，值是元素个数
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// 例如： array: [6, 4, 3, 1], counts: [empty, 1, empty, 1, 1, empty, 1]
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// i是元素, count是元素个数
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let sortedIndex = 0
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counts.forEach((count, i) => {
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while (count > 0) {
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array[sortedIndex] = i
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sortedIndex++
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count--
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}
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})
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// return array
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}
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function findMaxValue(array) {
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let max = array[0]
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for (let i = 1; i < array.length; i++) {
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if (array[i] > max) {
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max = array[i]
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}
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}
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return max
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}
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