chore: import upstream snapshot with attribution

greedy_algorithms/prims_minimum_spanning_tree.cpp

@@ -0,0 +1,64 @@
+#include <iostream>
+using namespace std;
+
+#define V 4
+#define INFINITY 99999
+
+int graph[V][V] = {{0, 5, 1, 2}, {5, 0, 3, 3}, {1, 3, 0, 4}, {2, 3, 4, 0}};
+
+struct mst {
+    bool visited;
+    int key;
+    int near;
+};
+
+mst MST_Array[V];
+
+void initilize() {
+    for (int i = 0; i < V; i++) {
+        MST_Array[i].visited = false;
+        MST_Array[i].key = INFINITY;  // considering INFINITY as inifinity
+        MST_Array[i].near = i;
+    }
+
+    MST_Array[0].key = 0;
+}
+
+void updateNear() {
+    for (int v = 0; v < V; v++) {
+        int min = INFINITY;
+        int minIndex = 0;
+        for (int i = 0; i < V; i++) {
+            if (MST_Array[i].key < min && MST_Array[i].visited == false &&
+                MST_Array[i].key != INFINITY) {
+                min = MST_Array[i].key;
+                minIndex = i;
+            }
+        }
+
+        MST_Array[minIndex].visited = true;
+
+        for (int i = 0; i < V; i++) {
+            if (graph[minIndex][i] != 0 && graph[minIndex][i] < INFINITY) {
+                if (graph[minIndex][i] < MST_Array[i].key) {
+                    MST_Array[i].key = graph[minIndex][i];
+                    MST_Array[i].near = minIndex;
+                }
+            }
+        }
+    }
+}
+
+void show() {
+    for (int i = 0; i < V; i++) {
+        cout << i << "  -  " << MST_Array[i].near << "\t"
+             << graph[i][MST_Array[i].near] << "\n";
+    }
+}
+
+int main() {
+    initilize();
+    updateNear();
+    show();
+    return 0;
+}