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@shawakash
Created August 2, 2024 09:08
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dsu
class DisjointSet {
vector<int> rank, parent, size;
public:
DisjointSet(int n) {
rank.resize(n + 1, 0);
parent.resize(n + 1);
size.resize(n + 1);
for (int i = 0; i <= n; i++) {
parent[i] = i;
size[i] = 1;
}
}
int findUPar(int node) {
if (node == parent[node])
return node;
return parent[node] = findUPar(parent[node]);
}
void unionByRank(int u, int v) {
int ulp_u = findUPar(u);
int ulp_v = findUPar(v);
if (ulp_u == ulp_v) return;
if (rank[ulp_u] < rank[ulp_v]) {
parent[ulp_u] = ulp_v;
}
else if (rank[ulp_v] < rank[ulp_u]) {
parent[ulp_v] = ulp_u;
}
else {
parent[ulp_v] = ulp_u;
rank[ulp_u]++;
}
}
void unionBySize(int u, int v) {
int ulp_u = findUPar(u);
int ulp_v = findUPar(v);
if (ulp_u == ulp_v) return;
if (size[ulp_u] < size[ulp_v]) {
parent[ulp_u] = ulp_v;
size[ulp_v] += size[ulp_u];
}
else {
parent[ulp_v] = ulp_u;
size[ulp_u] += size[ulp_v];
}
}
};
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