Update 1722.Minimize-Hamming-Distance-After-Swap-Operations.cpp

Author: wisdompeak

Union_Find/1722.Minimize-Hamming-Distance-After-Swap-Operations/1722.Minimize-Hamming-Distance-After-Swap-Operations.cpp

@@ -1,57 +1,53 @@
 class Solution {
  vector<int>Father;
+ int FindFather(int x)
+ {
+ if (Father[x]!=x)
+ Father[x] = FindFather(Father[x]);
+ return Father[x];
+ }
+ 
+ void Union(int x, int y)
+ {
+ x = Father[x];
+ y = Father[y];
+ if (x<y) Father[y] = x;
+ else Father[x] = y;
+ } 
+
 public:
- string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
- int N = s.size();
- Father.resize(N);
- for (int i=0; i<N; i++)
+ int minimumHammingDistance(vector<int>& source, vector<int>& target, vector<vector<int>>& allowedSwaps) 
+ {
+ int n = source.size();
+ Father.resize(n);
+ for (int i=0; i<n; i++)
  Father[i] = i;
 
- for (auto& p :pairs)
+ for (auto pair: allowedSwaps)
  {
- int a = p[0];
- int b = p[1];
+ int a = pair[0];
+ int b = pair[1];
  if (FindFather(a)!=FindFather(b))
  Union(a,b);
  }
 
- unordered_map<int, vector<int>>Map; // root idx -> all indexes
- for (int i=0; i<N; i++)
- {
+ unordered_map<int,vector<int>>Map;
+ for (int i=0; i<n; i++)
  Map[FindFather(i)].push_back(i);
- }
 
+ int count = 0;
  for (auto x: Map)
  {
- string temp;
- for (auto idx : x.second)
- temp.push_back(s[idx]);
- sort(temp.begin(),temp.end());
- int k = 0;
- for (auto idx : x.second)
+ multiset<int>Set;
+ for (auto i: x.second)
+ Set.insert(source[i]);
+ for (auto i: x.second)
  {
- s[idx] = temp[k];
- k++;
+ if (Set.find(target[i])!=Set.end())
+  Set.erase(Set.lower_bound(target[i]));
  }
+ count += Set.size();
  }
- 
- return s;
- }
- 
- int FindFather(int x)
- {
- if (Father[x]!=x)
- Father[x] = FindFather(Father[x]);
- return Father[x];
- }
- 
- void Union(int x, int y)
- {
- x = Father[x];
- y = Father[y];
- if (x<y)
- Father[y] = x;
- else
- Father[x] = y;
+ return count; 
  }
 };