From 9eaa71f94e551072a5c8f4d30139368e78b7875c Mon Sep 17 00:00:00 2001
From: David Rosca <roscadav@fit.cvut.cz>
Date: Mon, 9 Mar 2015 12:56:34 +0100
Subject: [PATCH] DFS: Change second variant to also offer canceling of
traversal
---
alib2algo/src/graph/traverse/Dfs.cpp | 8 +++++---
alib2algo/src/graph/traverse/Dfs.h | 4 ++--
alib2algo/test-src/graph/traverse/DfsTest.cpp | 2 ++
3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/alib2algo/src/graph/traverse/Dfs.cpp b/alib2algo/src/graph/traverse/Dfs.cpp
index 10094da155..1bef737f5c 100644
--- a/alib2algo/src/graph/traverse/Dfs.cpp
+++ b/alib2algo/src/graph/traverse/Dfs.cpp
@@ -42,18 +42,20 @@ static void dfs_impl(const T &graph, const Node &start, Dfs::Function func)
}
template <typename T>
-static void dfs2_impl(const T &graph, const Node &n, const Node &p, std::unordered_map<Node, bool> &visited, int &time, Dfs::FunctionExt func)
+static bool dfs2_impl(const T &graph, const Node &n, const Node &p, std::unordered_map<Node, bool> &visited, int &time, Dfs::FunctionExt func)
{
int opened = ++time;
visited[n] = true;
for (const Node &e : graph.neighbors(n)) {
if (visited.find(e) == visited.end()) {
- dfs2_impl(graph, e, n, visited, time, func);
+ if (!dfs2_impl(graph, e, n, visited, time, func)) {
+ return false;
+ }
}
}
- func(n, p, opened, ++time);
+ return func(n, p, opened, ++time);
}
void Dfs::dfs(const Graph &graph, const Node &start, Dfs::Function func)
diff --git a/alib2algo/src/graph/traverse/Dfs.h b/alib2algo/src/graph/traverse/Dfs.h
index f77ac7ac73..7f068d4d3b 100644
--- a/alib2algo/src/graph/traverse/Dfs.h
+++ b/alib2algo/src/graph/traverse/Dfs.h
@@ -14,13 +14,13 @@ namespace traverse
// func is called for each visited node, traversal stops when returning false
//
// bool Function(const Node &node);
-// void FunctionExt(const Node &node, const Node &predecessor, int openTime, int closeTime);
+// bool FunctionExt(const Node &node, const Node &predecessor, int openTime, int closeTime);
class Dfs : public graph::VisitableGraphBase::const_visitor_type
{
public:
typedef std::function<bool(const Node&)> Function;
- typedef std::function<void(const Node&, const Node&, int, int)> FunctionExt;
+ typedef std::function<bool(const Node&, const Node&, int, int)> FunctionExt;
static void dfs(const Graph &graph, const Node &start, Function func);
static void dfs(const Graph &graph, const Node &start, FunctionExt func);
diff --git a/alib2algo/test-src/graph/traverse/DfsTest.cpp b/alib2algo/test-src/graph/traverse/DfsTest.cpp
index 32541be9b9..4610da0315 100644
--- a/alib2algo/test-src/graph/traverse/DfsTest.cpp
+++ b/alib2algo/test-src/graph/traverse/DfsTest.cpp
@@ -188,6 +188,7 @@ void GraphDfsTest::testDfs2()
opened[n] = o;
closed[n] = c;
predecessors[n] = p;
+ return true;
});
CPPUNIT_ASSERT_EQUAL(5, counter);
@@ -216,6 +217,7 @@ void GraphDfsTest::testDfs2()
opened[n] = o;
closed[n] = c;
predecessors[n] = p;
+ return true;
});
CPPUNIT_ASSERT_EQUAL(5, counter);
--
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