Create longest-mountain-in-array.cpp

buyforgirl · Jun 3, 2018 · 3295aac · 3295aac
1 parent 08ef2a0
commit 3295aac
Showing 1 changed file with 21 additions and 0 deletions.
diff --git a/C++/longest-mountain-in-array.cpp b/C++/longest-mountain-in-array.cpp
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+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int longestMountain(vector<int>& A) {
+        int result = 0, up_len = 0, down_len = 0;
+        for (int i = 1; i < A.size(); ++i) {
+            if ((down_len && A[i - 1] < A[i]) ||
+                A[i - 1] == A[i]) {
+                up_len = down_len = 0;
+            }
+            up_len += A[i - 1] < A[i];
+            down_len += A[i - 1] > A[i];
+            if (up_len && down_len) {
+                result= max(result, up_len + down_len + 1);
+            }
+        }
+        return result;
+    }
+};