minor changes

Author: prince776

DataStructures/Graphs/dijkstra_shortest_path_algorithm.cpp

@@ -28,7 +28,7 @@ struct comparer
 {
 	bool operator()(pair<int, int> a, pair<int, int> b)
 	{
-		return a.second < b.second;
+		return a.second > b.second;
 	}	
 };
 

DataStructures/UnionFind/union_find.cpp

@@ -23,6 +23,7 @@ void Union_ineff(int parent[], int x, int y)
 struct subset
 {
 	int parent, rank;
+    subset() = default;
 	subset(int parent, int rank) :
 		parent(parent),
 		rank(rank)
@@ -31,30 +32,34 @@ struct subset
 	}
 };
 
-int find(subset subsets[], int i)
-{
-	// Path compression
-	if (subsets[i].parent != i)
-		subsets[i].parent = find(subsets, subsets[i].parent);
-
-	return subsets[i].parent;
-}
-
-int Union(subset subsets[], int x, int y)
-{
-	int xRoot = find(subsets, x);
-	int yRoot = find(subsets, y);
-
-	// Attach smaller rank tree under higher rank tree root
-	if (subsets[xRoot].rank < subsets[yRoot].rank)
-		subsets[xRoot].parent = yRoot;
-	if (subsets[yRoot].rank < subsets[xRoot].rank)
-		subsets[yRoot].parent = xRoot;
-
-	// If same rank, make one as root and increment the rank.
-	else
-	{
-		subsets[yRoot].parent = xRoot;
-		subsets[xRoot].rank++;
-	}
-}
+int find(struct subset subsets[], int i) 
+{ 
+    // find root and make root as parent of i (path compression) 
+    if (subsets[i].parent != i) 
+        subsets[i].parent = find(subsets, subsets[i].parent); 
+  
+    return subsets[i].parent; 
+} 
+  
+// A function that does union of two sets of x and y 
+// (uses union by rank) 
+void Union(struct subset subsets[], int x, int y) 
+{ 
+    int xroot = find(subsets, x); 
+    int yroot = find(subsets, y); 
+  
+    // Attach smaller rank tree under root of high rank tree 
+    // (Union by Rank) 
+    if (subsets[xroot].rank < subsets[yroot].rank) 
+        subsets[xroot].parent = yroot; 
+    else if (subsets[xroot].rank > subsets[yroot].rank) 
+        subsets[yroot].parent = xroot; 
+  
+    // If ranks are same, then make one as root and increment 
+    // its rank by one 
+    else
+    { 
+        subsets[yroot].parent = xroot; 
+        subsets[xroot].rank++; 
+    } 
+}