No commit message

Lib/UnionFindDisjointSets/unionfind_ds.cpp

@@ -0,0 +1,80 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+struct UnionFind
+{ 
+    private:
+    vector<int> p, rank, setSize;
+    int numSets;
+
+    public:
+    UnionFind(int N)
+    {
+        setSize.assign(N, 1);
+        numSets = N;
+        rank.assign(N, 0);
+        p.assign(N, 0);
+        for (int i = 0; i < N; i++)
+            p[i] = i;
+    }
+    int findSet(int i)
+    {
+        return (p[i] == i) ? i : (p[i] = findSet(p[i]));
+    }
+    bool isSameSet(int i, int j)
+    {
+        return findSet(i) == findSet(j);
+    }
+    void unionSet(int i, int j)
+    {
+        if (!isSameSet(i, j))
+        {
+            numSets--;
+            int x = findSet(i), y = findSet(j);
+            // rank is used to keep the tree short
+            if (rank[x] > rank[y])
+            {
+                p[y] = x;
+                setSize[x] += setSize[y];
+            }
+            else
+            {
+                p[x] = y;
+                setSize[y] += setSize[x];
+                if (rank[x] == rank[y])
+                    rank[y]++;
+            }
+        }
+    }
+
+    int numDisjointSets()
+    {
+        return numSets;
+    }
+    int sizeOfSet(int i)
+    {
+        return setSize[findSet(i)];
+    }
+};
+
+int main()
+{
+    printf("Assume that there are 5 disjoint sets initially\n");
+    UnionFind UF(5);                      // create 5 disjoint sets
+    printf("%d\n", UF.numDisjointSets()); // 5
+    UF.unionSet(0, 1);
+    printf("%d\n", UF.numDisjointSets()); // 4
+    UF.unionSet(2, 3);
+    printf("%d\n", UF.numDisjointSets()); // 3
+    UF.unionSet(4, 3);
+    printf("%d\n", UF.numDisjointSets());                 // 2
+    printf("isSameSet(0, 3) = %d\n", UF.isSameSet(0, 3)); // will return 0 (false)
+    printf("isSameSet(4, 3) = %d\n", UF.isSameSet(4, 3)); // will return 1 (true)
+    for (int i = 0; i < 5; i++)                           // findSet will return 1 for {0, 1} and 3 for {2, 3, 4}
+        printf("findSet(%d) = %d, sizeOfSet(%d) = %d\n", i, UF.findSet(i), i, UF.sizeOfSet(i));
+    UF.unionSet(0, 3);
+    printf("%d\n", UF.numDisjointSets()); // 1
+    for (int i = 0; i < 5; i++)           // findSet will return 3 for {0, 1, 2, 3, 4}
+        printf("findSet(%d) = %d, sizeOfSet(%d) = %d\n", i, UF.findSet(i), i, UF.sizeOfSet(i));
+    return 0;
+}

myCpps/!-OJcreater.cpp

@@ -12,7 +12,7 @@
 using namespace std;
 
 //***************************************
-const string CPPfile = "throughTheDesert_UVA11935"; //*
+const string CPPfile = "Friends_UVA10608"; //*
 //***************************************
 
 ifstream fin(CPPfile + ".cpp");

myCpps/Friends_UVA10608.cpp

@@ -0,0 +1,68 @@
+#include <algorithm>
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <list>
+#include <string>
+#include <vector>
+#include <set>
+#include <map>
+
+using namespace std;
+
+ifstream fin("Friends_UVA10608.in");
+ofstream fout("Friends_UVA10608.out");
+
+int _find(int u, vector<int> & p)
+{
+    if (p[u] == u)
+    {
+        return u;
+    }
+    else
+    {
+        int ans = _find(p[u], p);
+
+        p[u] = ans;
+
+        return ans;
+    }
+}
+
+int main()
+{
+    int testCaseTotal; fin >> testCaseTotal;
+
+    for (int t = 1; t <= testCaseTotal; ++t)
+    {
+        int n, m; fin >> n >> m;
+
+        vector<int> p(n + 1), g(n + 1, 0);
+        for (int i = 1; i <= n; ++i)
+        {
+            p[i] = i;
+        }
+
+        for (int c = 1; c <= m; ++c)
+        {
+            int u, v; fin >> u >> v;
+
+            p[_find(v, p)] = p[_find(u, p)];
+        }
+
+        int ans = 0;
+        for (int i = 1; i <= n; ++i)
+        {
+            ++g[_find(i, p)];
+
+            ans = max(ans, g[p[i]]);
+        }
+
+        fout << ans << '\n';
+    }
+
+    return 0;
+}

myCpps/Friends_UVA10608.in

@@ -0,0 +1,17 @@
+2
+3 2
+1 2
+2 3
+10 12
+1 2
+3 1
+3 4
+5 4
+3 5
+4 6
+5 2
+2 1
+7 1
+1 2
+9 10
+8 9

myCpps/Friends_UVA10608.out

@@ -0,0 +1,2 @@
+3
+7

myCpps/Friends_UVA10608OJ.cpp

@@ -0,0 +1,70 @@
+#include <algorithm>
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <list>
+#include <string>
+#include <vector>
+#include <set>
+#include <map>
+
+using namespace std;
+
+
+int _find(int u, vector<int> & p)
+{
+    if (p[u] == u)
+    {
+        return u;
+    }
+    else
+    {
+        int ans = _find(p[u], p);
+
+        p[u] = ans;
+
+        return ans;
+    }
+}
+
+int main()
+{
+	ios_base::sync_with_stdio(false);
+	std::cin.tie(NULL);
+    int testCaseTotal; cin >> testCaseTotal;
+
+    for (int t = 1; t <= testCaseTotal; ++t)
+    {
+        int n, m; cin >> n >> m;
+
+        vector<int> p(n + 1), g(n + 1, 0);
+        for (int i = 1; i <= n; ++i)
+        {
+            p[i] = i;
+        }
+
+        for (int c = 1; c <= m; ++c)
+        {
+            int u, v; cin >> u >> v;
+
+            p[_find(v, p)] = p[_find(u, p)];
+        }
+
+        int ans = 0;
+        for (int i = 1; i <= n; ++i)
+        {
+            ++g[_find(i, p)];
+
+            ans = max(ans, g[p[i]]);
+        }
+
+        cout << ans << '\n';
+    }
+
+   	cout.flush();
+   	return 0;
+}
+

myCpps/ubiquitousReligions_UVA10583.cpp

@@ -0,0 +1,69 @@
+#include <algorithm>
+#include <cmath>
+#include <cstdio>
+#include <cstdlib>
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <list>
+#include <string>
+#include <vector>
+#include <set>
+#include <map>
+
+using namespace std;
+
+ifstream fin("ubiquitousReligions_UVA10583.in");
+ofstream fout("ubiquitousReligions_UVA10583.out");
+
+int _find(int u, vector<int> & p)
+{
+    if (p[u] == u)
+    {
+        return u;
+    }
+    else
+    {
+        int ans = _find(p[u], p);
+
+        p[u] = ans;
+
+        return ans;
+    }
+}
+
+int main()
+{
+    int testCase = 0;
+    while (true)
+    {
+        ++testCase;
+
+        int n, m; fin >> n >> m;
+
+        if (n + m == 0) break;
+
+        vector<int> p(n + 1);
+        for (int i = 1; i <= n; ++i)
+        {
+            p[i] = i;
+        }
+
+        for (int c = 1; c <= m; ++c)
+        {
+            int u, v; fin >> u >> v;
+
+            p[_find(v, p)] = p[_find(u, p)];
+        }
+
+        set<int> s;
+        for (int i = 1; i <= n; ++i)
+        {
+            s.insert(_find(i, p));
+        }
+
+        fout << "Case " << testCase << ": " << s.size() << '\n';
+    }
+
+    return 0;
+}

myCpps/ubiquitousReligions_UVA10583.in

@@ -0,0 +1,49 @@
+10 9
+1 2
+1 3
+1 4
+1 5
+1 6
+1 7
+1 8
+1 9
+1 10
+10 4
+2 3
+4 5
+4 8
+5 8
+3 3
+1 1
+2 2
+3 3
+3 3
+1 1
+1 1
+1 1
+20 20
+12 4
+6 11
+17 7
+10 7
+7 17
+10 16
+14 16
+19 15                                                                                                         
+9 17                                                                                                          
+10 12                                                                                                         
+9 19
+9 15                                                                                                         
+5 15                                                                                                          
+19 11
+4 3
+10 13
+18 2
+8 18
+17 8
+12 17
+4 3
+1 2
+3 4
+1 3
+0 0

myCpps/ubiquitousReligions_UVA10583.out

@@ -0,0 +1,6 @@
+Case 1: 1
+Case 2: 7
+Case 3: 3
+Case 4: 3
+Case 5: 3
+Case 6: 1