46 lines
1.2 KiB
C++
46 lines
1.2 KiB
C++
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/**
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* File: worst_best_time_complexity.cpp
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* Created Time: 2022-11-25
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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><><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>飬Ԫ<E9A3AC><D4AA>Ϊ { 1, 2, ..., n }<7D><>˳<EFBFBD><EFBFBD><F2B1BBB4><EFBFBD> */
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vector<int> randomNumbers(int n) {
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vector<int> nums(n);
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> nums = { 1, 2, 3, ..., n }
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for (int i = 0; i < n; i++) {
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nums[i] = i + 1;
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}
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// ʹ<><CAB9>ϵͳʱ<CDB3><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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unsigned seed = chrono::system_clock::now().time_since_epoch().count();
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// <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ԫ<EFBFBD><D4AA>
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shuffle(nums.begin(), nums.end(), default_random_engine(seed));
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return nums;
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}
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/* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> nums <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
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int findOne(vector<int> &nums) {
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for (int i = 0; i < nums.size(); i++) {
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// <20><>Ԫ<EFBFBD><D4AA> 1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7>ʱ<EFBFBD><CAB1><EFBFBD>ﵽ<EFBFBD><EFB5BD><EFBFBD><EFBFBD>ʱ<EFBFBD>临<EFBFBD>Ӷ<EFBFBD> O(1)
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// <20><>Ԫ<EFBFBD><D4AA> 1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><CEB2>ʱ<EFBFBD><CAB1><EFBFBD>ﵽ<EFBFBD><EFB5BD><EFBFBD><EFBFBD>ʱ<EFBFBD>临<EFBFBD>Ӷ<EFBFBD> O(n)
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if (nums[i] == 1)
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return i;
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}
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return -1;
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}
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/* Driver Code */
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int main() {
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for (int i = 0; i < 1000; i++) {
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int n = 100;
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vector<int> nums = randomNumbers(n);
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int index = findOne(nums);
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cout << "\n<EFBFBD><EFBFBD><EFBFBD><EFBFBD> [ 1, 2, ..., n ] <20><><EFBFBD><EFBFBD><EFBFBD>Һ<EFBFBD> = ";
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printVector(nums);
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cout << "<EFBFBD><EFBFBD><EFBFBD><EFBFBD> 1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ " << index << endl;
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}
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return 0;
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}
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