Added solution for Longest Cycle in a Graph

vishal8113 · Oct 27, 2022 · b6c051b · b6c051b
1 parent 1450383
commit b6c051b
Showing 1 changed file with 14 additions and 0 deletions.
diff --git a/Longest_Cycle_in_a_Graph.cpp b/Longest_Cycle_in_a_Graph.cpp
@@ -0,0 +1,14 @@
+int longestCycle(vector<int>& edges) {
+    int n = edges.size(), ans = -1;
+    vector<int> idx(n);
+    for (int i = 0, k = 1; i < n; i++) {
+        int j = i, curk = k;
+        while (j != -1 && !idx[j]) {
+            idx[j] = k++;
+            j = edges[j];
+        }
+        if (j != -1 && idx[j] >= curk)
+            ans = max(ans, k - idx[j]);
+    }
+    return ans;
+}