Create 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

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+class Solution {
+ vector<int>Father;
+public:
+ string smallestStringWithSwaps(string s, vector<vector<int>>& pairs) {
+ int N = s.size();
+ Father.resize(N);
+ for (int i=0; i<N; i++)
+ Father[i] = i;
+ 
+ for (auto& p :pairs)
+ {
+ int a = p[0];
+ int b = p[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++)
+ {
+ Map[FindFather(i)].push_back(i);
+ }
+ 
+ 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)
+ {
+ s[idx] = temp[k];
+ k++;
+ }
+ }
+ 
+ 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;
+ }
+};