41 lines
874 B
C++
41 lines
874 B
C++
#include <vector>
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#include <unordered_set>
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#include <unordered_map>
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/**
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* 532. K-diff Pairs in an Array
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* Given an array of integers nums and an integer k, return the number of unique k-diff pairs in the array.
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* A k-diff pair is an integer pair (nums[i], nums[j]), where the following are true:
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* - 0 <= i, j < nums.length
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* - i != j
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* - nums[i] - nums[j] == k
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* Notice that |val| denotes the absolute value of val.
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*
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* Refer: 220209.cpp
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*/
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class Solution {
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public:
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static int findPairs(const std::vector<int>& nums, int k) {
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int ans = 0;
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if (k) {
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std::unordered_set<int> s;
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for (int i : nums) {
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if (s.count(i))
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continue;
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if (s.count(i + k))
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++ans;
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if (s.count(i - k))
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++ans;
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s.insert(i);
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}
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} else {
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std::unordered_map<int, int> m;
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for (int i : nums)
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if (m[i]++ == 1)
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++ans;
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}
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return ans;
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}
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};
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