Create jump-game-iii.cpp

Author: kamyu104

C++/jump-game-iii.cpp

@@ -0,0 +1,23 @@
+// Time:  O(n)
+// Space: O(n)
+
+class Solution {
+public:
+    bool canReach(vector<int>& arr, int start) {
+        queue<int> q({start});
+        unordered_set<int> lookup = {start};
+        while (!q.empty()) {
+            const auto i = q.front(); q.pop();
+            if (!arr[i]) {
+                return true;
+            }
+            for (const auto& j : {i - arr[i], i + arr[i]}) {
+                if (0 <= j && j < arr.size() && !lookup.count(j)) {
+                    lookup.emplace(j);
+                    q.emplace(j);
+                }
+            }
+        }
+        return false;
+    }
+};