def copyAndReverse(arr):
# Write your code here
a=arr[::-1]
return a
Problem of the day
You are given an array 'ARR' consisting of 'N' non-negative integers, your task is to copy the elements of 'ARR' into another array 'COPY_ARR' in reverse order.
For example:
If 'ARR' contains the following elements [ 1, 2, 3, 4, 5 ], then you should return another array that is equal to [ 5, 4, 3, 2, 1].
The first line of the input contains a single integer T, denoting the number of test cases.
The first line of each test case contains a single integer N, denoting the length of the array 'ARR'.
The second line of each test case contains N space-separated integers, denoting the elements of the array.
Output Format :
For each test case print, N space-separated integers, where the ith integer denotes the ith element of the array 'COPY_ARR'.
Note:
You do not need to print anything. It has already been taken care of. Just implement the given function.
1 <= T <= 10^2
1 <= N <= 10^4
0 <= ARR[i] <= 10^9
Time Limit: 1 sec
2
5
1 2 3 4 5
4
5 8 2 1
5 4 3 2 1
1 2 8 5
The reverse of [1, 2, 3, 4, 5] is [5, 4, 3, 2,1]
The reverse of [5, 8, 2, 1] is [1, 2, 8, 5].
3
3
3 2 1
4
8 6 2 4
5
1 3 5 4 2
1 2 3
4 2 6 8
2 4 5 3 1
The reverse of [3, 2, 1] is [1, 2, 3].
The reverse of [8, 6, 2, 4] is [4, 2, 6, 8].
The reverse of [1, 3, 5, 4, 2] is [2, 4, 5, 3, 1].
Try to go from end to beginning in the ARR.
O(N) , where N is the length of the array ARR.
The time complexity is O(N) because we are traversing the complete array of N elements
O(1).
As we are using constant extra memory.
Interview problems
Reverse the array. Python
def copyAndReverse(arr):
# Write your code here
a=arr[::-1]
return a
Interview problems
simplest solution using while loop (C++)
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
// Write your code here.
vector<int> ans;
int s =0,e=n-1;
while(s<=e){
ans.push_back(arr[e]);
e--;
}
return ans;
}
Interview problems
I solution this question with C++ and Python, here is the solution 😎
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
// Write your code here.
vector<int>reverseArr;
for(int i=0; i<n; i++){
reverseArr.push_back(arr[n-1-i]);
}
return reverseArr;
}
from os import *
from sys import *
from collections import *
from math import *
def copyAndReverse(arr):
# Write your code here
arr.reverse()
return arr
Interview problems
A one line c++ code!!!
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
reverse(arr.begin(),arr.end());
return arr;
}
Interview problems
C++ Easy Solution
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
// Write your code here.
vector<int>ans(arr);
reverse(ans.begin(),ans.end());
return ans;
}
Interview problems
Perfect Solution
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
// Write your code here.
vector<int> nums;
for(int i=n-1;i>=0;i--)
{
nums.push_back(arr[i]);
}
return nums;
}
Interview problems
Easy Solution || Java
import java.util.* ;
import java.io.*;
public class Solution {
public static int[] copyAndReverse(int[] arr, int n) {
// Write your code here.
int p=n-1;
for(int i=0;i<n/2;i++){
int temp=arr[i];
arr[i]=arr[p];
arr[p]=temp;
p--;
}
return arr;
}
}
Interview problems
C++ solution without using reverse function
vector<int>v;
for(int i=n-1; i>=0; i--){
v.push_back(arr[i]);
}
return v;
Interview problems
ONELINER CODE 🔥
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
// Write your code here.
reverse(arr.begin(),arr.end());
return arr;
}
Interview problems
3 line code
#include <bits/stdc++.h>
vector<int> copyAndReverse(vector<int> arr, int n) {
// Write your code here.
vector<int> copy;
for(int i = n-1; i >=0; i--) copy.push_back(arr[i]);
return copy;
}