add: 230325-CN

cpp/2303/230325-CN.cpp

@@ -0,0 +1,49 @@
+#include <vector>
+#include <map>
+#include <algorithm>
+
+int findLengthOfShortestSUBSEQUENCE(const std::vector<int>& arr) {
+	const int n = arr.size();
+	std::map<int, int> m;
+	std::vector<int> dp(n);
+	m[arr[0]] = dp[0] = 1;
+	int ans = 1;
+	for (int i = 1; i < n; ++i) {
+		auto it = m.upper_bound(arr[i]);
+		if (it == m.begin())
+			ans = std::max(ans, m[arr[i]] = dp[i] = 1);
+		else
+			ans = std::max(ans, m[arr[i]] = dp[i] = 1 + (--it)->second);
+	}
+	return n - ans;
+}
+
+/**
+ * 1574. Shortest Subarray to be Removed to Make Array Sorted
+ *
+ * Given an integer array arr, remove a subarray (can be empty) from arr such that the remaining elements in arr are non-decreasing.
+ * Return the length of the shortest subarray to remove.
+ * A subarray is a contiguous subsequence of the array.
+ */
+
+class Solution {
+public:
+	static int findLengthOfShortestSubarray(const std::vector<int>& arr) {
+		const int n = arr.size();
+		const int* d = arr.data();
+		int L = 0, R = n - 1;
+		for (; L + 1 < n && d[L + 1] >= d[L]; ++L);
+		for (; R && d[R - 1] <= d[R]; --R);
+		if (L >= R)
+			return 0;
+		int ans = ++L;
+		for (int i = n - 1; i >= R; --i)
+			ans = std::max(ans, int(std::upper_bound(d, d + L, d[i]) - d + n - i));
+		return n - ans;
+	}
+};
+
+int main() {
+	Solution::findLengthOfShortestSubarray({10,13,17,21,15,15,9,17,22,22,13});
+	return 0;
+}