66 lines
1.9 KiB
C++
66 lines
1.9 KiB
C++
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/**
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* File: radix_sort.cpp
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* Created Time: 2023-03-26
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* Author: krahets (krahets@163.com)
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*/
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#include "../utils/common.hpp"
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/* <20><>ȡԪ<C8A1><D4AA> num <20>ĵ<EFBFBD> k λ<><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD> exp = 10^(k-1) */
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int digit(int num, int exp) {
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// <20><><EFBFBD><EFBFBD> exp <20><><EFBFBD><EFBFBD> k <20><><EFBFBD>Ա<EFBFBD><D4B1><EFBFBD><EFBFBD>ڴ<EFBFBD><DAB4>ظ<EFBFBD>ִ<EFBFBD>а<EFBFBD><D0B0><EFBFBD><EFBFBD>Ĵη<C4B4><CEB7><EFBFBD><EFBFBD><EFBFBD>
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return (num / exp) % 10;
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}
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/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><F2A3A8B8><EFBFBD> nums <20><> k λ<><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
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void countingSortDigit(vector<int> &nums, int exp) {
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// ʮ<><CAAE><EFBFBD>Ƶ<EFBFBD>λ<EFBFBD><CEBB>ΧΪ 0~9 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>Ϊ 10 <20><>Ͱ<EFBFBD><CDB0><EFBFBD><EFBFBD>
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vector<int> counter(10, 0);
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int n = nums.size();
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// ͳ<><CDB3> 0~9 <20><><EFBFBD><EFBFBD><EFBFBD>ֵij<D6B5><C4B3>ִ<EFBFBD><D6B4><EFBFBD>
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for (int i = 0; i < n; i++) {
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int d = digit(nums[i], exp); // <20><>ȡ nums[i] <20><> k λ<><CEBB><EFBFBD><EFBFBD>Ϊ d
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counter[d]++; // ͳ<><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD> d <20>ij<EFBFBD><C4B3>ִ<EFBFBD><D6B4><EFBFBD>
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}
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// <20><>ǰ<C7B0>ͣ<EFBFBD><CDA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><D7AA>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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for (int i = 1; i < 10; i++) {
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counter[i] += counter[i - 1];
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}
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ͱ<EFBFBD><CDB0>ͳ<EFBFBD>ƽ<EFBFBD><C6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD> res
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vector<int> res(n, 0);
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for (int i = n - 1; i >= 0; i--) {
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int d = digit(nums[i], exp);
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int j = counter[d] - 1; // <20><>ȡ d <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD> j
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res[j] = nums[i]; // <20><><EFBFBD><EFBFBD>ǰԪ<C7B0><D4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> j
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counter[d]--; // <20><> d <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1
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}
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// ʹ<>ý<EFBFBD><C3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԭ<EFBFBD><D4AD><EFBFBD><EFBFBD> nums
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for (int i = 0; i < n; i++)
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nums[i] = res[i];
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}
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/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
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void radixSort(vector<int> &nums) {
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// <20><>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD>أ<EFBFBD><D8A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><D0B6><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><CEBB>
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int m = *max_element(nums.begin(), nums.end());
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// <20><><EFBFBD>մӵ<D5B4>λ<EFBFBD><CEBB><EFBFBD><EFBFBD>λ<EFBFBD><CEBB>˳<EFBFBD><CBB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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for (int exp = 1; exp <= m; exp *= 10)
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD>صĵ<D8B5> k λִ<CEBB>м<EFBFBD><D0BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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// k = 1 -> exp = 1
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// k = 2 -> exp = 10
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// <20><> exp = 10^(k-1)
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countingSortDigit(nums, exp);
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}
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/* Driver Code */
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int main() {
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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vector<int> nums = {10546151, 35663510, 42865989, 34862445, 81883077,
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88906420, 72429244, 30524779, 82060337, 63832996};
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radixSort(nums);
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cout << "<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɺ<EFBFBD> nums = ";
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printVector(nums);
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return 0;
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}
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