From 96a6a9151f4e44e134f6394d76444a55ff4d4e7e Mon Sep 17 00:00:00 2001
From: Shubham Marathe <76870563+shubhammarathe15@users.noreply.github.com>
Date: Sat, 29 Oct 2022 00:38:14 +0530
Subject: [PATCH] Create Longest Increasing subsequence

---
 Longest Increasing subsequence | 40 ++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 Longest Increasing subsequence

diff --git a/Longest Increasing subsequence b/Longest Increasing subsequence
new file mode 100644
index 0000000..f66fba7
--- /dev/null
+++ b/Longest Increasing subsequence	
@@ -0,0 +1,40 @@
+
+#include <bits/stdc++.h>
+#include <iostream>
+using namespace std;
+
+
+int f(int idx, int prev_idx, int n, int a[],
+	vector<vector<int> >& dp)
+{
+	if (idx == n) {
+		return 0;
+	}
+
+	if (dp[idx][prev_idx + 1] != -1) {
+		return dp[idx][prev_idx + 1];
+	}
+
+	int notTake = 0 + f(idx + 1, prev_idx, n, a, dp);
+	int take = INT_MIN;
+	if (prev_idx == -1 || a[idx] > a[prev_idx]) {
+		take = 1 + f(idx + 1, idx, n, a, dp);
+	}
+
+	return dp[idx][prev_idx + 1] = max(take, notTake);
+}
+
+int longestSubsequence(int n, int a[])
+{
+	vector<vector<int> > dp(n + 1, vector<int>(n + 1, -1));
+	return f(0, -1, n, a, dp);
+}
+
+
+int main()
+{
+	int a[] = { 3, 10, 2, 1, 20 };
+	int n = sizeof(a) / sizeof(a[0]);
+	cout << "Length of lis is " << longestSubsequence(n, a);
+	return 0;
+}