graph connected components

Author: ivorynoise

Diff for: 459-d.cpp

@@ -0,0 +1,73 @@
+#include <bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+typedef vector<ll> vi;
+typedef vector<vi> vvi;
+const int mod = 1000000007;
+const int sze = 100010;
+vi g[30];
+
+int toInt(char c) { return c - 'A';}
+
+void bfs(int src, vector<bool>& visited) {
+
+	queue<int> q;
+	q.push(src);
+	visited[src] = true;
+
+	while(!q.empty()){
+		int cur = q.front();
+		q.pop();
+
+		for(int i = 0; i < (int)g[cur].size(); ++i){
+			int v = g[cur][i];
+			if (visited[v] == false){
+				q.push(v);
+				visited[v] = true;
+			}
+		}
+	}
+
+}
+
+int connectedComponents(int n){
+	vector<bool> visited;
+	visited.assign(n, false);
+	int cc = 0;
+
+	for (int ver = 0; ver < n; ++ver) {
+		if (!visited[ver]) {
+			bfs(ver, visited);
+			++cc;
+		}
+	}
+	return cc;
+}
+
+
+int main() {
+	int t;
+	cin >> t;
+	char inp[100];
+	cin.getline(inp, 100);	//consumes all the whitespace after t
+	cin.getline(inp , 100);	//consumes the first line
+
+	while (t--) {
+		char n; cin >> n;
+		int N = toInt(n) + 1;
+
+		cin.getline(inp, 100);
+		//reading edges
+
+		while (cin.getline(inp, 100) && strlen(inp) > 0) {
+			g[toInt(inp[0])].push_back(toInt(inp[1]));
+			g[toInt(inp[1])].push_back(toInt(inp[0]));
+		}
+
+		cout << connectedComponents(N) << "\n";
+		//output of the two consecutive shall be seperated by a blank line
+		if (t) 
+			cout << "\n";
+		for(auto& v : g) v.clear();	//clearing all adjlists in the g array
+	}
+}