- Accept 09_04_two_pointers
- Get basic_test.cpp
Please read the Guidelines for pointers before you begin.
Implement following three functions without brute force (nested loop).
Given an array arr sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same.
Since it is impossible to change the length of the array in some languages, you must instead have the result be placed in the first part of the array arr. More formally, The first size elements of arr should hold the final result. It does not matter what you leave beyond the first size elements.
Do not allocate extra space for another array. You must do this by modifying the input array in-place without extra memory.
Input: arr = [1,1,2]
Output: arr = [1,2,_], size = 2
Explanation: Your function should change size = 2, with the first two elements of arr being 1 and 2 respectively.
It does not matter what you leave beyond the size (hence they are underscores).
Input: arr = [0,0,1,1,1,2,2,3,3,4]
Output: arr = [0,1,2,3,4,_,_,_,_,_], size = 5
Explanation: Your function should change size = 5, with the first five elements of arr being 0, 1, 2, 3, and 4 respectively.
It does not matter what you leave beyond the size (hence they are underscores).
Input: arr = [a,a,a,b,b,c,c,c,c,d,e,e,f,g,g,h]
Output: arr = [a,b,c,d,e,f,g,h], size = 8
1 <= nums.length <= 99-99 <= nums[i] <= 99numsis sorted in non-decreasing order.
We need to modify the array in-place and the size of the final array would potentially be smaller than the size of the input array. So, we ought to use a two-pointer approach here. One, that would keep track of the current element in the original array and another one for just the unique elements.
Given a 1-indexed array of integers numbers that is already sorted in non-decreasing order, find two numbers such that they add up to a specific target number. Let these two numbers be numbers[index1] and numbers[index2] where 1 <= index1 < index2 <= numbers.length.
Return the pointer of indices of the two numbers, index1 and index2, added by one as an integer array [index1, index2] of length 2.
The tests are generated such that there is exactly one solution. You may not use the same element twice.
Your solution must use only constant extra space.
Input: numbers = [2,7,11,15], target = 9
Output: [1,2]
Explanation: The sum of 2 and 7 is 9. Therefore, index1 = 1, index2 = 2. We return [1, 2].
Input: numbers = [2,3,4], target = 6
Output: [1,3]
Explanation: The sum of 2 and 4 is 6. Therefore index1 = 1, index2 = 3. We return [1, 3].
Input: numbers = [-1,0], target = -1
Output: [1,2]
Explanation: The sum of -1 and 0 is -1. Therefore index1 = 1, index2 = 2. We return [1, 2].
2 <= numbers.length <= 99-99 <= numbers[i] <= 99numbersis sorted in non-decreasing order.-99 <= target <= 99- The tests are generated such that there is exactly one solution.
Given an array of characters s. Find the length of the longest substring without repeating characters.
Input: s = [a,b,c,a,b,c,b,b]
Output: 3
Explanation: The answer is "abc", with the length of 3.
Input: s = [b,b,b,b,b]
Output: 1
Explanation: The answer is "b", with the length of 1.
Input: s =[p,w,w,k,e,w]
Output: 3
Explanation: The answer is "wke", with the length of 3.
Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.
0 <= s.length <= 99sconsists of English lowercase letters (a-z).
Implement following functions in includes/two_pointers/two_pointers.h
#ifndef TWO_POINTERS_H
#define TWO_POINTERS_H
#include <iostream>
using namespace std;
// Declaration
template<typename T>
void removeDuplicates(T* arr, int& size);
template<typename T>
int* twoSum(T* numbers, const int size, int target);
template<typename T>
int lengthOfLongestSubstring(T* s, const int size);
// Definition
// TODO
#endif // TWO_POINTERS_H