added bfs in c++

1 files changed, 69 insertions, 0 deletions

diff --git a/cpp/bfs.cc b/cpp/bfs.cc
new file mode 100644
index 0000000..8174030
--- /dev/null
+++ b/cpp/bfs.cc
@@ -0,0 +1,69 @@
+#include <iostream>
+#include <list>
+#include <queue>
+
+#define WHITE 0
+#define GREY 1
+#define BLACK 2
+#define INF 99999
+
+using namespace std;
+
+int checked[INF] = {WHITE};
+int d[INF] = {0};
+int f[INF] = {0};
+int t = 1;
+
+void bfs(const list<int> lista[], int start) {
+    queue<int> coda;
+
+    int checked[999] = {WHITE};
+    
+    coda.push(start);
+    
+    checked[start] = GREY;
+    while(!coda.empty()) {
+        int corrente = coda.front();
+        coda.pop();
+
+        if(checked[corrente] == GREY) {
+            cout << corrente << ' ';
+            for(auto it = lista[corrente].begin(); it != lista[corrente].end(); ++it) {
+                coda.push(*it);
+                if(checked[*it] != BLACK)
+                    checked[*it] = GREY;
+            }
+            checked[corrente] = BLACK;
+        }
+    }
+}
+
+int main() {
+	int u, w;
+	int e;
+	cin >> e;
+	list<int> lista[INF];
+	for(int i = 0; i < e; ++i) {
+		cin >> u >> w;
+		lista[u].push_back(w);
+	}
+
+	bfs(lista, 0); //0 is the start
+	
+	/* example:
+	http://pages.cs.wisc.edu/~mcw/cs367/lectures/images/bfs.gif
+	#input
+	8
+	0 1
+	0 5
+	1 2
+	2 0
+	1 3
+	3 4
+	4 2
+	1 4
+	#output
+	0 1 5 2 3 4
+	*/
+	return 0;
+}