# Fair Pay - Amazon Top Interview Questions

### Problem Statement :

```You are given a list of integers ratings representing the performance scores of programmers. The manager would like to give \$1 to every programmer except if two programmers are adjacent, they'd like to pay the better performing programmer at least \$1 higher than the worse performing one.

Return the minimum amount of dollars the manager can pay following above constraints.

Constraints

n ≤ 100,000 where n is the length of ratings.

Example 1

Input

ratings = [1, 2, 5, 1]

Output

7

Explanation

The minimum we can pay for each respective programmer is [1, 2, 3, 1]```

### Solution :

```                        ```Solution in C++ :

vector<int> left(r.size(), 1), right(r.size(), 1);
for  (int i=1; i<r.size(); i++) {
if (r[i] > r[i-1]) left[i] = left[i-1] + 1;
}
for (int i=r.size()-2; i>=0; i--) {
if (r[i] > r[i+1]) right[i] = right[i+1] + 1;
}

int ans = 0;
for (int i=0; i<r.size(); i++) ans += max(left[i], right[i]);
return ans;```
```

```                        ```Solution in Java :

import java.util.*;

class Solution {
public int solve(int[] ratings) {
if (ratings.length == 0)
return 0;
int[] left = new int[ratings.length];
int[] right = new int[ratings.length];
left = 1;
for (int i = 1; i < ratings.length; i++) {
if (ratings[i] > ratings[i - 1]) {
left[i] = (1 + left[i - 1]);
} else
left[i] = 1;
}
right[ratings.length - 1] = 1;
for (int i = ratings.length - 2; i >= 0; i--) {
if (ratings[i] > ratings[i + 1]) {
right[i] = 1 + right[i + 1];
} else
right[i] = 1;
}
// System.out.println(Arrays.toString(left));
// System.out.println(Arrays.toString(right));
int[] pay = new int[ratings.length];
int cnt = 0;
for (int i = 0; i < ratings.length; i++) {
pay[i] = Math.max(left[i], right[i]);
cnt += pay[i];
}
return cnt;
}
}```
```

```                        ```Solution in Python :

class Solution:
def solve(self, ratings):
if not ratings:
return 0
n = len(ratings)
up = down = peak = 0
res = 1
for i in range(1, n):
if ratings[i - 1] < ratings[i]:
# going up case
up += 1
peak = up
down = 0
# 1 basic pay + up amount based on previous chain of increasing ratings
res += 1 + up
elif ratings[i - 1] == ratings[i]:
up = down = peak = 0
res += 1
else:
up = 0
down += 1
# down amount for chain of decreasing ratings + 1 basic pay if previous peak is smaller than current
res += down
if peak < down:
res += 1
return res```
```

## Reverse a doubly linked list

This challenge is part of a tutorial track by MyCodeSchool Given the pointer to the head node of a doubly linked list, reverse the order of the nodes in place. That is, change the next and prev pointers of the nodes so that the direction of the list is reversed. Return a reference to the head node of the reversed list. Note: The head node might be NULL to indicate that the list is empty.

## Tree: Preorder Traversal

Complete the preorder function in the editor below, which has 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's preorder traversal as a single line of space-separated values. Input Format Our test code passes the root node of a binary tree to the preOrder function. Constraints 1 <= Nodes in the tree <= 500 Output Format Print the tree's

## Tree: Postorder Traversal

Complete the postorder function in the editor below. It received 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's postorder traversal as a single line of space-separated values. Input Format Our test code passes the root node of a binary tree to the postorder function. Constraints 1 <= Nodes in the tree <= 500 Output Format Print the

## Tree: Inorder Traversal

In this challenge, you are required to implement inorder traversal of a tree. Complete the inorder function in your editor below, which has 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's inorder traversal as a single line of space-separated values. Input Format Our hidden tester code passes the root node of a binary tree to your \$inOrder* func

## Tree: Height of a Binary Tree

The height of a binary tree is the number of edges between the tree's root and its furthest leaf. For example, the following binary tree is of height : image Function Description Complete the getHeight or height function in the editor. It must return the height of a binary tree as an integer. getHeight or height has the following parameter(s): root: a reference to the root of a binary

## Tree : Top View

Given a pointer to the root of a binary tree, print the top view of the binary tree. The tree as seen from the top the nodes, is called the top view of the tree. For example : 1 \ 2 \ 5 / \ 3 6 \ 4 Top View : 1 -> 2 -> 5 -> 6 Complete the function topView and print the resulting values on a single line separated by space.