From 2ea5133eecab7be3ba7bc4d90fa8050b4eeee819 Mon Sep 17 00:00:00 2001
From: kindofman <43539680+kindofman@users.noreply.github.com>
Date: Sun, 1 Dec 2019 20:29:37 +0300
Subject: [PATCH 1/4] Update main.cpp

---
 11-2/main.cpp | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)

diff --git a/11-2/main.cpp b/11-2/main.cpp
index b8e507b..cfcc56b 100644
--- a/11-2/main.cpp
+++ b/11-2/main.cpp
@@ -5,3 +5,85 @@
 Вывод: количество кратчайших путей от v к w.
 
 ссылка на Яндекс.Контест https://contest.yandex.ru/contest/15957/run-report/27592154/
+
+#include <iostream>
+#include <algorithm>
+#include <queue>
+#include <unordered_map>
+#include <assert.h>
+#include <list>
+#include <vector>
+
+using std::list;
+using std::vector;
+using std::queue;
+using std::cout;
+
+void BFS(vector<int> *adj, int src, int dist[], int* paths, int n) {
+    bool* visited = new bool[n];
+    for (int i = 0; i < n; i++)
+        visited[i] = false;
+    dist[src] = 0;
+    paths[src] = 1;
+  
+    queue <int> q;
+    q.push(src);
+    visited[src] = true;
+    while (!q.empty()) {
+        int curr = q.front();
+        q.pop();
+  
+        for (auto x : adj[curr]) {
+            if (visited[x] == false) {
+                q.push(x);
+                visited[x] = true;
+            }
+            if (dist[x] > dist[curr] + 1) {
+                dist[x] = dist[curr] + 1;
+                paths[x] = paths[curr];
+            }
+            else if (dist[x] == dist[curr] + 1)
+                paths[x] += paths[curr];
+        }
+    }
+    delete[] visited;
+}
+  
+int find_shortest_paths(vector<int> *adj, int s, int n, int w) {
+    int dist[n];
+    int* paths = new int[n];
+    for (int i = 0; i < n; i++)
+        dist[i] = 2147483647;
+    for (int i = 0; i < n; i++)
+        paths[i] = 0;
+    BFS(adj, s, dist, paths, n);
+    int result = paths[w];
+    delete[] paths;
+	return result;
+}
+  
+void add_edge(vector<int> *adj, int u, int v) {
+    adj[u].push_back(v);
+}
+
+
+int main() {
+    int v_, n;
+    std::cin >> v_ >> n;
+    vector <int>* adj = new vector <int>[v_];
+    
+    for ( int i = 0; i < n; ++i ) {
+        int u, v;
+        std::cin >> u >> v;
+        add_edge(adj, u, v);
+        add_edge(adj, v, u);
+    }
+    int v, w;
+    std::cin >> v >> w;
+    int result = find_shortest_paths(adj, v, v_, w);
+	  cout << result << std::endl;
+    delete[] adj;
+  
+    return 0;
+}
+

From a26b727e7cc4ef2590e0082d2a3cbb650f2c42b6 Mon Sep 17 00:00:00 2001
From: kindofman <43539680+kindofman@users.noreply.github.com>
Date: Sun, 8 Dec 2019 10:31:54 +0300
Subject: [PATCH 2/4] Update main.cpp

---
 11-2/main.cpp | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/11-2/main.cpp b/11-2/main.cpp
index cfcc56b..2bf2fd8 100644
--- a/11-2/main.cpp
+++ b/11-2/main.cpp
@@ -13,13 +13,25 @@
 #include <assert.h>
 #include <list>
 #include <vector>
+#define INT_MAX 2147483647
 
 using std::list;
 using std::vector;
 using std::queue;
 using std::cout;
 
-void BFS(vector<int> *adj, int src, int dist[], int* paths, int n) {
+class Graph {
+public:
+    Graph(int v): v(v) { adj.assign(v, {}); };
+    void BFS( vector<vector <int> > adj, int src, int dist[], int* paths, int n );
+    int find_shortest_paths( int s, int n, int w );
+    void add_edge( int u, int v );
+private:
+    const int v;
+    vector<vector <int> > adj;
+};
+
+void Graph::BFS( vector<vector <int> > adj, int src, int dist[], int* paths, int n ) {
     bool* visited = new bool[n];
     for (int i = 0; i < n; i++)
         visited[i] = false;
@@ -49,41 +61,40 @@ void BFS(vector<int> *adj, int src, int dist[], int* paths, int n) {
     delete[] visited;
 }
   
-int find_shortest_paths(vector<int> *adj, int s, int n, int w) {
+int Graph::find_shortest_paths( int s, int n, int w ) {
     int dist[n];
     int* paths = new int[n];
     for (int i = 0; i < n; i++)
-        dist[i] = 2147483647;
+        dist[i] = INT_MAX;
     for (int i = 0; i < n; i++)
         paths[i] = 0;
     BFS(adj, s, dist, paths, n);
     int result = paths[w];
     delete[] paths;
-	return result;
+    return result;
 }
   
-void add_edge(vector<int> *adj, int u, int v) {
+void Graph::add_edge( int u, int v ) {
     adj[u].push_back(v);
+    adj[v].push_back(u);
 }
 
-
 int main() {
     int v_, n;
     std::cin >> v_ >> n;
-    vector <int>* adj = new vector <int>[v_];
-    
+    Graph g(v_);
     for ( int i = 0; i < n; ++i ) {
         int u, v;
         std::cin >> u >> v;
-        add_edge(adj, u, v);
-        add_edge(adj, v, u);
+        g.add_edge( u, v );
     }
     int v, w;
     std::cin >> v >> w;
-    int result = find_shortest_paths(adj, v, v_, w);
-	  cout << result << std::endl;
-    delete[] adj;
+    int result = g.find_shortest_paths( v, v_, w );
+      cout << result << std::endl;
   
     return 0;
 }
 
+
+

From 541c639c8fed0580614c1760a7bc378fb4d491c4 Mon Sep 17 00:00:00 2001
From: kindofman <43539680+kindofman@users.noreply.github.com>
Date: Sat, 14 Dec 2019 12:24:51 +0300
Subject: [PATCH 3/4] Update main.cpp

---
 11-2/main.cpp | 53 +++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 6 deletions(-)

diff --git a/11-2/main.cpp b/11-2/main.cpp
index 2bf2fd8..a1f3957 100644
--- a/11-2/main.cpp
+++ b/11-2/main.cpp
@@ -23,18 +23,16 @@ using std::cout;
 class Graph {
 public:
     Graph(int v): v(v) { adj.assign(v, {}); };
-    void BFS( vector<vector <int> > adj, int src, int dist[], int* paths, int n );
-    int find_shortest_paths( int s, int n, int w );
+    void BFS( int src, vector<int>& dist, vector<int>& paths, int n ) const;
+    int find_shortest_paths( int s, int n, int w ) const;
     void add_edge( int u, int v );
 private:
     const int v;
     vector<vector <int> > adj;
 };
 
-void Graph::BFS( vector<vector <int> > adj, int src, int dist[], int* paths, int n ) {
-    bool* visited = new bool[n];
-    for (int i = 0; i < n; i++)
-        visited[i] = false;
+void Graph::BFS( int src, vector<int>& dist, vector<int>& paths, int n ) const {
+    vector<bool> visited( n, false );
     dist[src] = 0;
     paths[src] = 1;
   
@@ -58,6 +56,49 @@ void Graph::BFS( vector<vector <int> > adj, int src, int dist[], int* paths, int
                 paths[x] += paths[curr];
         }
     }
+}
+  
+int Graph::find_shortest_paths( int s, int n, int w ) const {
+    vector<int> dist( n, INT_MAX );
+    vector<int> paths( n, 0 );
+    BFS( s, dist, paths, n );
+    int result = paths[w];
+    return result;
+}
+  
+void Graph::add_edge( int u, int v ) {
+    adj[u].push_back(v);
+    adj[v].push_back(u);
+}
+
+int main() {
+    int v_, n;
+    std::cin >> v_ >> n;
+    Graph g(v_);
+    for ( int i = 0; i < n; ++i ) {
+        int u, v;
+        std::cin >> u >> v;
+        g.add_edge( u, v );
+    }
+    int v, w;
+    std::cin >> v >> w;
+    int result = g.find_shortest_paths( v, v_, w );
+      cout << result << std::endl;
+  
+    return 0;
+}
+
+
+                visited[x] = true;
+            }
+            if (dist[x] > dist[curr] + 1) {
+                dist[x] = dist[curr] + 1;
+                paths[x] = paths[curr];
+            }
+            else if (dist[x] == dist[curr] + 1)
+                paths[x] += paths[curr];
+        }
+    }
     delete[] visited;
 }
   

From cbc02487688af046a3e76c840373ffee09dd528d Mon Sep 17 00:00:00 2001
From: kindofman <43539680+kindofman@users.noreply.github.com>
Date: Sat, 14 Dec 2019 12:33:52 +0300
Subject: [PATCH 4/4] Update main.cpp

---
 11-2/main.cpp | 51 ---------------------------------------------------
 1 file changed, 51 deletions(-)

diff --git a/11-2/main.cpp b/11-2/main.cpp
index a1f3957..991493f 100644
--- a/11-2/main.cpp
+++ b/11-2/main.cpp
@@ -88,54 +88,3 @@ int main() {
     return 0;
 }
 
-
-                visited[x] = true;
-            }
-            if (dist[x] > dist[curr] + 1) {
-                dist[x] = dist[curr] + 1;
-                paths[x] = paths[curr];
-            }
-            else if (dist[x] == dist[curr] + 1)
-                paths[x] += paths[curr];
-        }
-    }
-    delete[] visited;
-}
-  
-int Graph::find_shortest_paths( int s, int n, int w ) {
-    int dist[n];
-    int* paths = new int[n];
-    for (int i = 0; i < n; i++)
-        dist[i] = INT_MAX;
-    for (int i = 0; i < n; i++)
-        paths[i] = 0;
-    BFS(adj, s, dist, paths, n);
-    int result = paths[w];
-    delete[] paths;
-    return result;
-}
-  
-void Graph::add_edge( int u, int v ) {
-    adj[u].push_back(v);
-    adj[v].push_back(u);
-}
-
-int main() {
-    int v_, n;
-    std::cin >> v_ >> n;
-    Graph g(v_);
-    for ( int i = 0; i < n; ++i ) {
-        int u, v;
-        std::cin >> u >> v;
-        g.add_edge( u, v );
-    }
-    int v, w;
-    std::cin >> v >> w;
-    int result = g.find_shortest_paths( v, v_, w );
-      cout << result << std::endl;
-  
-    return 0;
-}
-
-
-