BFS-2.1 completed

EmployeeImportance.cpp

@@ -0,0 +1,39 @@
+/*
+// Definition for Employee.
+class Employee {
+public:
+    int id;
+    int importance;
+    vector<int> subordinates;
+};
+*/
+
+class Solution {
+public:
+    int getImportance(vector<Employee*> employees, int id) {
+        unordered_map<int, vector<int>> idsMap;
+        unordered_map<int, Employee*> usEmp;
+        vector<int> inorder;
+        for (int i=0;i<employees.size();i++) {
+            idsMap[employees[i]->id] = employees[i]->subordinates;
+            usEmp[employees[i]->id] = employees[i];
+        }
+
+        queue<int> q;
+        q.push(id);
+        int answer = usEmp[id]->importance;
+
+        while (!q.empty()) {
+            auto node = q.front();
+            q.pop();
+
+            vector<int> direct = idsMap[node];
+            for (int i=0;i<direct.size();i++) {
+                answer += usEmp[direct[i]]->importance;
+                q.push(direct[i]);
+            }
+        }
+
+        return answer;
+    }
+};

RottingOranges.cpp

@@ -0,0 +1,62 @@
+class Solution {
+public:
+    vector<vector<int>> dirs = {{1,0}, {-1,0}, {0,1}, {0,-1}};
+    int orangesRotting(vector<vector<int>>& grid) {
+    queue<pair<int ,int>> q;
+    unordered_set<string> us, freshO;
+
+    auto key = [&](int x, int y) {
+        return to_string(x)+"+"+to_string(y);
+    };
+
+    auto markVisited = [&](int x, int y) {
+        string str = key(x, y);
+        us.insert(str);
+        freshO.erase(str);
+    };
+
+    auto isSafe = [&](int x, int y) {
+        if (x >= 0 && y >= 0 && x < grid.size() && y <grid[0].size()) {
+            return true;
+        }
+        return false;
+    };
+
+    for (int i=0;i<grid.size();i++) {
+        for (int j=0;j<grid[0].size();j++) {
+            if (grid[i][j] == 2) {
+                q.push({i,j});
+                // grid[i][j] = 0;
+                markVisited(i, j);
+            } else if (grid[i][j] == 1) {
+                freshO.insert(key(i, j));
+            }
+        }
+    }
+
+
+    int time = -1;
+    if (freshO.empty() && us.empty()) return 0;
+
+    while (!q.empty()) {
+        int size = q.size();
+        while (size--) {
+            auto node = q.front();
+            q.pop();
+
+            for (int i=0;i<dirs.size();i++) {
+                int newX = node.first + dirs[i][0];
+                int newY = node.second + dirs[i][1];
+
+                if (isSafe(newX, newY) && !us.contains(key(newX, newY)) && grid[newX][newY] == 1) {
+                    markVisited(newX, newY);
+                    grid[newX][newY] = 2;
+                    q.push({newX, newY});
+                }
+            }
+        }
+        time++;
+    }
+    return freshO.empty() ? time : -1;
+    }
+};