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-rw-r--r--longest_path_diff_char.cpp36
1 files changed, 36 insertions, 0 deletions
diff --git a/longest_path_diff_char.cpp b/longest_path_diff_char.cpp
new file mode 100644
index 0000000..8eb9878
--- /dev/null
+++ b/longest_path_diff_char.cpp
@@ -0,0 +1,36 @@
+#include "leetcode.h"
+
+class Solution {
+public:
+ int longestPath(vector<int> &parent, string s) {
+ int n = parent.size(), ans = 1;
+ queue<int> q;
+ vector<int> cnt(n), top1(n, 1), top2(n, 1);
+ for (int i = 1; i < n; ++i)
+ ++cnt[parent[i]];
+ for (int i = 1; i < n; ++i)
+ if (cnt[i] == 0)
+ q.push(i);
+ while (!q.empty() && q.front() != 0) {
+ int i = q.front(), p = parent[i];
+ q.pop();
+ if (int len = 1 + (s[i] != s[p] ? top1[i] : 0); top1[p] <= len) {
+ top2[p] = top1[p];
+ top1[p] = len;
+ } else
+ top2[p] = max(top2[p], len);
+ if (--cnt[p] == 0) {
+ q.push(p);
+ ans = max(ans, top1[p] + top2[p] - 1);
+ }
+ }
+ return ans;
+ }
+};
+
+int main() {
+ Solution obj;
+ vector<int> parent1 = {-1, 0, 0, 1, 1, 2}, parent2 = {-1, 0, 0, 0};
+ cout << obj.longestPath(parent1, "abacbe") << endl; // expect: 3
+ cout << obj.longestPath(parent2, "aabc") << endl; // expect: 3
+}