feat: add graph with matrix instead of list

1 files changed, 81 insertions, 0 deletions

diff --git a/I_anno/Programmazione_2/data_structures/matrix-graph.cc b/I_anno/Programmazione_2/data_structures/matrix-graph.cc
new file mode 100644
index 0000000..a644ec1
--- /dev/null
+++ b/I_anno/Programmazione_2/data_structures/matrix-graph.cc
@@ -0,0 +1,81 @@
+#include<iostream>
+#include<list>
+
+using namespace std;
+
+template<class H>
+class matrix_graph {
+public:
+    ~matrix_graph() {
+        delete[] _m;
+        delete[] _k;
+    }
+    matrix_graph(int len) : _len{len}, _nodes{0}, _edges{0} {
+        _m = new int*[len];
+        _k = new H*[len];
+        for(int i = 0; i < len; ++i) {
+            _m[i] = new int[len];
+            _k[i] = nullptr;
+            for(int j = 0; j < len; ++j)
+                _m[i][j] = 0;
+        }
+    }
+
+    matrix_graph<H>* add_node(H k) {
+        if(_len == _nodes) return this; // no more space for new nodes
+        if(_index(k) > -1) return this; // nodes already exists
+
+        _k[_nodes++] = new H(k);
+
+        return this;
+    }
+
+    matrix_graph<H>* add_edge(H x, H y) {
+        int i = _index(x);
+        int j = _index(y);
+        if(i < 0 || j < 0) return this;
+        if(!_m[i][j]) {
+            _m[i][j] = 1;
+            _edges++;
+        }
+        return this;
+    }
+    void print() {
+        for(int i = 0; i < _len; ++i) {
+            cout << i << ' ' << *_k[i] << ": ";
+            for(int j = 0; j < _len; ++j) {
+                if(_m[i][j])
+                    cout << *_k[j] << ' ';
+            }
+            cout << '\n';
+        }
+        cout << endl;
+        for(int i = 0; i < _len; ++i) {
+            for(int j = 0; j < _len; ++j) {
+                cout << _m[i][j] << ' ';
+            }
+            cout << '\n';
+        }
+    }
+private:
+    int _len, _nodes, _edges;
+    int** _m;
+    H** _k;
+    int _index(H x) {
+        for(int i = 0; i < _nodes; ++i)
+            if(*_k[i] == x) return i;
+        return -1;
+    }
+};
+
+int main() {
+    matrix_graph<string>* g = new matrix_graph<string>(5);
+    g->add_node("hello")->add_node("greg")->add_node("yes");
+    g->add_node("nop")->add_node("ok");
+    g->add_edge("hello", "ok");
+    g->add_edge("ok", "yes")->add_edge("yes", "ok")->add_edge("yes", "yes");
+    g->add_edge("yes", "nop");
+    g->print();
+    delete g;
+    return 0;
+}