Method unionBySize

KruskalsAlgorithm.java:51–67

(int node1, int node2)

        return parent[node];
    }
    public boolean unionBySize(int node1, int node2){
        //1. find the root parent
        int rootParent1 = findRootParent(node1);
        int rootParent2 = findRootParent(node2);
        if(rootParent1==rootParent2){
            return false;
        }
        // 2, union of components
        if(size[rootParent1]<size[rootParent2]){
            parent[rootParent1] = rootParent2;
            size[rootParent2] += size[rootParent1];
        }else {
            parent[rootParent2] = rootParent1;
            size[rootParent1] += size[rootParent2];
        }
        return true;
    }
}