- Difficulty: Medium
- Tags: LeetCode, Medium, Graph, Topological Sort, leetcode-1059, Depth-First Search, O(n + e), 🔒
Problem
Given the edges
of a directed graph where edges[i] = [ai, bi]
indicates there is an edge between nodes ai
and bi
, and two nodes source
and destination
of this graph, determine whether or not all paths starting from source
eventually, end at destination
, that is:
- At least one path exists from the
source
node to thedestination
node - If a path exists from the
source
node to a node with no outgoing edges, then that node is equal todestination
. - The number of possible paths from
source
todestination
is a finite number.
Return true
if and only if all roads from source
lead to destination
.
Â
Example 1:
Input: n = 3, edges = [[0,1],[0,2]], source = 0, destination = 2 Output: false Explanation: It is possible to reach and get stuck on both node 1 and node 2.
Example 2:
Input: n = 4, edges = [[0,1],[0,3],[1,2],[2,1]], source = 0, destination = 3 Output: false Explanation: We have two possibilities: to end at node 3, or to loop over node 1 and node 2 indefinitely.
Example 3:
Input: n = 4, edges = [[0,1],[0,2],[1,3],[2,3]], source = 0, destination = 3 Output: true
Â
Constraints:
1 <= n <= 104
0 <= edges.length <= 104
edges.length == 2
0 <= ai, bi <= n - 1
0 <= source <= n - 1
0 <= destination <= n - 1
- The given graph may have self-loops and parallel edges.