Create shortest-subarray-to-be-removed-to-make-array-sorted.cpp

Author: kamyu104

C++/shortest-subarray-to-be-removed-to-make-array-sorted.cpp

@@ -0,0 +1,60 @@
+// Time:  O(n)
+// Space: O(1)
+
+class Solution {
+public:
+    int findLengthOfShortestSubarray(vector<int>& arr) {
+        int j;
+        for (j = arr.size() - 1; j >= 1; --j) {
+            if (arr[j - 1] > arr[j]) {
+                break;
+            }
+        }
+        if (j == 0) {
+            return 0;
+        }
+        int result = j;
+        for (int i = 0; i < arr.size(); ++i) {
+            if (i && arr[i - 1] > arr[i]) {
+                break;
+            }
+            while (j < arr.size() && arr[i] > arr[j]) {
+                ++j;
+            }
+            result = min(result, (j - i + 1) - 2);
+        }
+        return result;
+    }
+};
+
+// Time:  O(n)
+// Space: O(1)
+class Solution2 {
+public:
+    int findLengthOfShortestSubarray(vector<int>& arr) {
+        int result = 0;
+        for (int i = 1; i < arr.size(); ++i) {
+            if (arr[i - 1] <= arr[i]) {
+                continue;
+            }
+            int j = arr.size() - 1;
+            while (j > i && (j == arr.size() - 1 || arr[j] <= arr[j + 1]) && arr[i - 1] <= arr[j]) {
+                --j;
+            }
+            result = j - i + 1;
+            break;
+        }
+        for (int j = arr.size() - 2; j >= 0; --j) {
+            if (arr[j] <= arr[j + 1]) {
+                continue;
+            }
+            int i = 0;
+            while (i < j && (i == 0 || arr[i - 1] <= arr[i]) && arr[i] <= arr[j + 1]) {
+                ++i;
+            }
+            result = min(result, j - i + 1);
+            break;
+        }
+        return result;
+    }
+};