25 lines
646 B
C++
25 lines
646 B
C++
#include <vector>
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#include <bitset>
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/**
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* 442. Find All Duplicates in an Array
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* Given an integer array nums of length n where all the integers of nums are in the range [1, n] and each integer appears once or twice, return an array of all the integers that appears twice.
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* You must write an algorithm that runs in O(n) time and uses only constant extra space.
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*/
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class Solution {
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public:
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static std::vector<int> findDuplicates(const std::vector<int>& nums) {
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std::bitset<100001> s;
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std::vector<int> v;
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v.reserve(nums.size());
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for (auto i : nums) {
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if (s.test(i))
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v.push_back(i);
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else
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s.set(i);
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}
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return v;
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}
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};
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