replaced recursion DFS to stack DFS

replaced recursion DFS to stack DFS

modules/text/src/text_detector_swt.cpp

@@ -7,6 +7,7 @@
 
 #include <unordered_map>
 #include <limits>
+#include <stack>
 
 using namespace std;
 
@@ -91,15 +92,25 @@ void addEdge(std::vector< std::vector<int> >& adj, int u, int v)
 static
 void DFSUtil(int v, std::vector<bool> & visited, std::vector< std::vector<int> >& adj, int label, std::vector<int> &component_id)
 {
-    // Mark the current node as visited and label it as belonging to the current component
-    visited[v] = true;
-    component_id[v] = label;
-    // Recur for all the vertices
-    // adjacent to this vertex
-    for (size_t i = 0; i < adj[v].size(); i++) {
-        int neighbour = adj[v][i];
-        if (!visited[neighbour]) {
-            DFSUtil(neighbour, visited, adj, label, component_id);
+    stack<int> s;
+    s.push(v);
+    while(!s.empty()){
+        v = s.top();
+        s.pop();
+        if(!visited[v])
+        {
+            // Mark the current node as visited and label it as belonging to the current component
+            visited[v] = true;
+            component_id[v] = label;
+            // Recur for all the vertices
+            // adjacent to this vertex
+            for (size_t i = 0; i < adj[v].size(); i++) {
+                int neighbour = adj[v][i];
+                if(!visited[neighbour])
+                {
+                    s.push(neighbour);
+                }
+            }
         }
     }
 }