day 15

Author: sachuverma

Leetcode Daily Challenge/January-2021/15. Get Maximum in Generated Array.cpp

@@ -0,0 +1,73 @@
+/*
+Get Maximum in Generated Array
+===============================
+
+You are given an integer n. An array nums of length n + 1 is generated in the following way:
+
+nums[0] = 0
+nums[1] = 1
+nums[2 * i] = nums[i] when 2 <= 2 * i <= n
+nums[2 * i + 1] = nums[i] + nums[i + 1] when 2 <= 2 * i + 1 <= n
+Return the maximum integer in the array nums​​​.
+
+Example 1:
+Input: n = 7
+Output: 3
+Explanation: According to the given rules:
+  nums[0] = 0
+  nums[1] = 1
+  nums[(1 * 2) = 2] = nums[1] = 1
+  nums[(1 * 2) + 1 = 3] = nums[1] + nums[2] = 1 + 1 = 2
+  nums[(2 * 2) = 4] = nums[2] = 1
+  nums[(2 * 2) + 1 = 5] = nums[2] + nums[3] = 1 + 2 = 3
+  nums[(3 * 2) = 6] = nums[3] = 2
+  nums[(3 * 2) + 1 = 7] = nums[3] + nums[4] = 2 + 1 = 3
+Hence, nums = [0,1,1,2,1,3,2,3], and the maximum is 3.
+
+Example 2:
+Input: n = 2
+Output: 1
+Explanation: According to the given rules, the maximum between nums[0], nums[1], and nums[2] is 1.
+
+Example 3:
+Input: n = 3
+Output: 2
+Explanation: According to the given rules, the maximum between nums[0], nums[1], nums[2], and nums[3] is 2.
+
+Constraints:
+0 <= n <= 100
+
+Hint #1  
+Try generating the array.
+
+Hint #2  
+Make sure not to fall in the base case of 0.
+*/
+
+class Solution
+{
+public:
+  int getMaximumGenerated(int n)
+  {
+    n++;
+    if (n <= 2)
+      return n - 1;
+    vector<int> arr(n, -1);
+    arr[0] = 0;
+    arr[1] = 1;
+    int ans = INT_MIN;
+
+    for (int i = 2; i < n; ++i)
+    {
+      if (i % 2 == 0)
+      {
+        arr[i] = arr[i / 2];
+      }
+      else
+        arr[i] = arr[(i - 1) / 2] + arr[(i + 1) / 2];
+      ans = max(ans, arr[i]);
+    }
+
+    return ans;
+  }
+};

Leetcode Daily Challenge/January-2021/README.md

@@ -16,4 +16,5 @@
 | 12.  | [Add Two Numbers](https://leetcode.com/explore/challenge/card/january-leetcoding-challenge-2021/580/week-2-january-8th-january-14th/3601/) | [cpp](./12.%20Add%20Two%20Numbers.cpp) |
 | 13.  | [Boats to Save People](https://leetcode.com/explore/challenge/card/january-leetcoding-challenge-2021/580/week-2-january-8th-january-14th/3602/) | [cpp](./13.%20Boats%20to%20Save%20People.cpp) |
 | 14.  | [Minimum Operations to Reduce X to Zero](https://leetcode.com/explore/challenge/card/january-leetcoding-challenge-2021/580/week-2-january-8th-january-14th/3603/) | [cpp](./14.%20Minimum%20Operations%20to%20Reduce%20X%20to%20Zero.cpp) |
+| 15.  | [Get Maximum in Generated Array](https://leetcode.com/explore/challenge/card/january-leetcoding-challenge-2021/581/week-3-january-15th-january-21st/3605/) | [cpp](./15.%20Get%20Maximum%20in%20Generated%20Array.cpp) |
 | .  | []() | [cpp](./.cpp) |