Merge pull request neetcode-gh#2704 from tahzeer/patch-3

Create 0399-evaluate-division.cpp

cpp/0399-evaluate-division.cpp

@@ -0,0 +1,57 @@
+class Solution {
+ unordered_map<string, vector<pair<string, double>>> graph;
+ unordered_map<string, bool> visited;
+ double queryAns;
+
+public:
+ bool dfs(string startNode, string endNode, double runningProduct){
+ if(graph.find(startNode) == graph.end() || graph.find(endNode) == graph.end()) {
+ return false;
+ }
+
+ if(startNode == endNode && graph.find(startNode)!=graph.end()) {
+ queryAns = runningProduct;
+ return true;
+
+ }
+
+ bool tempAns = false;
+ visited[startNode] = true;
+
+ for(int i = 0; i < graph[startNode].size(); i++){
+ if(!visited[graph[startNode][i].first]){
+ tempAns = dfs(graph[startNode][i].first, endNode, runningProduct*graph[startNode][i].second);
+ if(tempAns){
+ break;
+ }
+ }
+ }
+ visited[startNode] = false;
+
+ return tempAns;
+ }
+
+ vector<double> calcEquation(vector<vector<string>>& equations, vector<double>& values, vector<vector<string>>& queries) {
+ int n = equations.size(), m = queries.size();
+ vector<double> ans(m);
+
+ for(int i = 0; i < n ; i++){
+
+ graph[equations[i][0]].push_back({equations[i][1], values[i]});
+ graph[equations[i][1]].push_back({equations[i][0], 1/values[i]});
+ visited[equations[i][0]] = false;
+ visited[equations[i][1]] = false;
+
+ }
+
+ for(int i = 0; i < m ; i++){
+
+ queryAns = 1;
+ bool pathFound = dfs(queries[i][0], queries[i][1], 1); 
+ if(pathFound) ans[i] = queryAns;
+ else ans[i] = -1;
+
+ }
+ return ans;
+ }
+};