[C++] Add solution for Horror List

Solutions/Horror List/horror.cpp

@@ -0,0 +1,52 @@
+#include <iostream>
+#include <vector>
+#include <unordered_map>
+#include <unordered_set>
+#include <algorithm>
+#include <queue>
+
+using namespace std;
+
+typedef vector<int> vi;
+typedef unordered_set<int> usi;
+
+int main() {
+    int num_movies, num_horrors, similarities;
+    cin >> num_movies >> num_horrors >> similarities;
+
+    queue<int> q;
+    vi horror_rating(num_movies, 1e9);
+    for(int i = 0; i < num_horrors; ++i) {
+        int id;
+        cin >> id;
+        q.push(id);
+        horror_rating[id] = 0;
+    }
+
+    vector<vi> adjacency_list(num_movies);
+    while(similarities--) {
+        int a, b;
+        cin >> a >> b;
+        adjacency_list[a].push_back(b);
+        adjacency_list[b].push_back(a);
+    }
+
+    while(!q.empty()) {
+        int current_id = q.front(); q.pop();
+        for(int neighbor : adjacency_list[current_id]) {
+            if(horror_rating[neighbor] > horror_rating[current_id] + 1) {
+                horror_rating[neighbor] = horror_rating[current_id] + 1;
+                q.push(neighbor);
+            }
+        }
+    }
+
+    int current_max = *max_element(horror_rating.begin(), horror_rating.begin() + num_movies);
+    for(int i = 0; i < num_movies; ++i) {
+        if(horror_rating[i] == current_max) {
+            cout << i;
+            break;
+        }
+    }
+    return 0;
+}