Shortest Sublist to Remove to Make Sorted List - Amazon Top Interview Questions
Problem Statement :
Given a list of integers nums, return the length of the shortest sublist that you can remove such that the resulting list is in ascending order. Constraints n ≤ 100,000 where n is the length of nums Example 1 Input nums = [1, 1, 3, 5, 4, 2, 1, 9] Output 3 Explanation If we remove [4, 2, 1], then the list would be sorted in ascending order: [1, 1, 3, 5, 9].
Solution :
Solution in C++ :
int solve(vector<int>& nums) {
{
bool issorted = true;
for (int i = 1; i < nums.size() && issorted; i++) {
issorted = nums[i] >= nums[i - 1];
}
if (issorted) return 0;
}
int prefixsize = 1;
for (int i = 1; i < nums.size(); i++) {
if (nums[i] < nums[i - 1]) break;
prefixsize++;
}
int suffixsize = 1;
for (int i = nums.size() - 2; i >= 0; i--) {
if (nums[i] > nums[i + 1]) break;
suffixsize++;
}
int ret = suffixsize;
int j = 0;
for (int i = 0; i < prefixsize; i++) {
while (j < suffixsize && nums[nums.size() - suffixsize + j] < nums[i]) j++;
ret = max(ret, i + 1 + suffixsize - j);
}
return nums.size() - ret;
}
Solution in Java :
import java.util.*;
class Solution {
public int solve(int[] nums) {
final int N = nums.length;
if (N < 2)
return 0;
boolean[] leftvalid = new boolean[N];
leftvalid[0] = true;
for (int i = 1; i != N; i++) leftvalid[i] = leftvalid[i - 1] && (nums[i] >= nums[i - 1]);
boolean[] rightvalid = new boolean[N];
rightvalid[N - 1] = true;
for (int i = N - 2; i != -1; i--)
rightvalid[i] = rightvalid[i + 1] && (nums[i] <= nums[i + 1]);
if (rightvalid[0])
return 0;
int l = 1, h = N - 2;
while (l <= h) {
int m = (l + h) >>> 1;
if (can(nums, leftvalid, rightvalid, m))
h = m - 1;
else
l = m + 1;
}
return l;
}
private boolean can(int[] nums, boolean[] left, boolean[] right, final int K) {
if (left[left.length - K - 1] || right[K])
return true;
for (int i = 1, j = K; j + 1 != left.length; i++, j++)
if (left[i - 1] && right[j + 1] && nums[i - 1] <= nums[j + 1])
return true;
return false;
}
}
View More Similar Problems
Array-DS
An array is a type of data structure that stores elements of the same type in a contiguous block of memory. In an array, A, of size N, each memory location has some unique index, i (where 0<=i<N), that can be referenced as A[i] or Ai. Reverse an array of integers. Note: If you've already solved our C++ domain's Arrays Introduction challenge, you may want to skip this. Example: A=[1,2,3
View Solution →2D Array-DS
Given a 6*6 2D Array, arr: 1 1 1 0 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 An hourglass in A is a subset of values with indices falling in this pattern in arr's graphical representation: a b c d e f g There are 16 hourglasses in arr. An hourglass sum is the sum of an hourglass' values. Calculate the hourglass sum for every hourglass in arr, then print t
View Solution →Dynamic Array
Create a list, seqList, of n empty sequences, where each sequence is indexed from 0 to n-1. The elements within each of the n sequences also use 0-indexing. Create an integer, lastAnswer, and initialize it to 0. There are 2 types of queries that can be performed on the list of sequences: 1. Query: 1 x y a. Find the sequence, seq, at index ((x xor lastAnswer)%n) in seqList.
View Solution →Left Rotation
A left rotation operation on an array of size n shifts each of the array's elements 1 unit to the left. Given an integer, d, rotate the array that many steps left and return the result. Example: d=2 arr=[1,2,3,4,5] After 2 rotations, arr'=[3,4,5,1,2]. Function Description: Complete the rotateLeft function in the editor below. rotateLeft has the following parameters: 1. int d
View Solution →Sparse Arrays
There is a collection of input strings and a collection of query strings. For each query string, determine how many times it occurs in the list of input strings. Return an array of the results. Example: strings=['ab', 'ab', 'abc'] queries=['ab', 'abc', 'bc'] There are instances of 'ab', 1 of 'abc' and 0 of 'bc'. For each query, add an element to the return array, results=[2,1,0]. Fun
View Solution →Array Manipulation
Starting with a 1-indexed array of zeros and a list of operations, for each operation add a value to each of the array element between two given indices, inclusive. Once all operations have been performed, return the maximum value in the array. Example: n=10 queries=[[1,5,3], [4,8,7], [6,9,1]] Queries are interpreted as follows: a b k 1 5 3 4 8 7 6 9 1 Add the valu
View Solution →