graph problem

Author: piyushkhemka

Diff for: 323. Number of Connected Components.cpp

@@ -0,0 +1,35 @@
+class Solution {
+
+    void dfs(int key, unordered_map<int, vector<int> > &relation, unordered_set<int> &visited) {
+        visited.insert(key);
+        for(auto it = relation[key].begin(); it!= relation[key].end(); it++) {
+            if(visited.find(*it) == visited.end())
+                dfs(*it, relation, visited);
+        }
+    }
+
+public:
+    int countComponents(int n, vector<pair<int, int>>& edges) {
+
+        unordered_map<int, vector<int> > relation;
+        unordered_set<int> visited;
+
+        for(auto i: edges) {
+            relation[i.first].push_back(i.second);
+            relation[i.second].push_back(i.first);
+        }
+
+        int count = 0;
+
+        for(int i = 0;i<n;i++) {
+            if(visited.find(i) == visited.end()) {
+                count++;
+                dfs(i, relation, visited);
+            }
+        }
+
+        return count;
+
+
+    }
+};

Diff for: Non-leetcode/Implement your own sizeof.cpp

@@ -0,0 +1,8 @@
+#define my_sizeof(type) (char *)(&type+1)-(char*)(&type)
+int main()
+{
+    double x;
+    printf("%d", my_sizeof(x));
+    getchar();
+    return 0;
+}