532. K-diff Pairs in an Array
Given an array of integers nums and an integer k, return the number of unique k-diff pairs in the array.
A k-diff pair is an integer pair (nums[i], nums[j]), where the following are true:
- 0 <= i, j < nums.length
- i != j
- |nums[i] - nums[j]| == k
Notice that |val| denotes the absolute value of val.
- new solution update 2022.02.09
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| class Solution {
public:
int findPairs(vector<int>& nums, int k) {
unordered_set<int> s, dup;
int res = 0;
for(int i = 0; i < nums.size(); i++) {
if(s.count(nums[i])) {
if(!k and !dup.count(nums[i])) {
res++;
dup.insert(nums[i]);
}
} else {
res += s.count(nums[i] - k);
res += s.count(nums[i] + k);
s.insert(nums[i]);
}
}
return res;
}
};
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| class Solution {
public:
int findPairs(vector<int>& nums, int k) {
int res = 0;
unordered_map<int, int> m;
for(auto& num : nums) {
m[num]++;
}
if(k == 0) {
for(auto& num : m) {
if(num.second >= 2)
res++;
}
} else {
for(auto& num : m) {
if(m.count(num.first + k))
res++;
}
}
return res;
}
};
|
