Almost increasing sequence

Question

1.00/5 (1 vote)

See more:

/*Given a sequence of integers as an array(vector), determine whether it is possible to obtain a strictly
 * increasing sequence by removing no more than one element from the array.*/

#include <iostream>
#include <vector>
using namespace std;
bool almostIncreasingSequence(std::vector<int> sequence)
{
    int count=0;
    int i=0;

    while(i<sequence.size())
        {
            if(sequence[i]>sequence[i+1])
                {
                    count++;
                }
            i++;

        }
        if(count>1)
            {
            return false;}
        else
            {
                return true;
            }
            i++;
}


int main()
{
    vector<int>arr{1,6,5,8,9};
    cout<<almostIncreasingSequence(arr)<<endl;


}

What I have tried:

I am trying to compile this code correctly, but I don't understand what is my mistake

Posted 24-Oct-17 21:10pm

Member 13277493

Updated 14-Oct-22 10:00am

Add a Solution

Comments

OriginalGriff 25-Oct-17 3:19am

What's the error?
Where is it showing?

Member 13277493 25-Oct-17 4:33am

this is a problem in codefights website, they are some tests that this problem does not pass.

3 solutions

Solution 2

bool almostIncreasingSequence(std::vector<int> sequence) {
if (sequence.size() == 1) return true;

int count = 0;
for (int i = 0; i < sequence.size() - 1; i++)
{
if (sequence[i + 1] <= sequence[i])
{
if (sequence[i+1] > sequence[i-1] || i == 0)
sequence.erase(sequence.begin() + i);
else if (sequence[i+1] <= sequence[i-1])
sequence.erase(sequence.begin() + (i+1));
break;
}
}
for (int i = 0; i < sequence.size() - 1; i++)
{
if (sequence[i + 1] <= sequence[i])
return false;
}

return true;

}

Posted 26-Apr-21 9:02am

Tatev Hunanyan

Comments

Stefan_Lang 27-Apr-21 3:15am

This question is many years old. Unless you have to add something really important, please do not answer such old postings.

More importantly, a code dump without explanations is not a solution! If you wish to provide any help at all, the most important thing is explain. Providing code is merely an afterthought to help illustrate your explanation.

Solution 3

i solved using this php code

function solution($sequence) {
$count = count($sequence);
$c_copy = $count;
$i=0;
$step = 0;

while($i<=$count-2){
if($count==1 || $count==2 && $count==$c_copy){
return true;
}
if($sequence[$i]>=$sequence[$i+1]){
if($i+1==$count-1 || $sequence[$i-1]>=$sequence[$i+1]){
unset($sequence[$i+1]);
$temp = array_values($sequence);
$sequence = $temp;
$step++;
$count--;
$i--;
if($step==2){
return false;
}
}
else{unset($sequence[$i]);
$temp = array_values($sequence);
$sequence = $temp;
$step++;
$count--;
$i--;
if($step==2){
return false;
}
}

}
else if($sequence[$i]<$sequence[$i+1]){
$i++;
}
if($i==$count-2 && $sequence[$i]<$sequence[$i+1]){
return true;
}
}
}

Posted 14-Oct-22 10:00am

Member 15798074

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

CPallini · Accepted Answer · 2017-10-24T21:35:00

Solution 1

You immediate problem is

Quote:
while(i<sequence.size())

You have to change it to

C++

while(i < (sequence.size() - 1) )

However that's not enough.
First of all you have to replace > with >= in comparisons (because it should be a strictly increasing sequence), then you shoud try to remove either sequence[i] or sequence[i+1], accepting the first one that preserves locally the incresing property. Lastly 'you can work on points of style' e.g. return false whenever count>1 instead of waiting the end of the loop.

Posted 24-Oct-17 21:35pm

CPallini

Comments

Member 13277493 25-Oct-17 5:00am

#include <iostream>
#include <vector>
using namespace std;
bool almostIncreasingSequence(std::vector<int> sequence)
{
int count=0;
int i=0;

while(i<sequence.size()-1)
{
if(sequence[i]>=sequence[i+1])
{
count++;
sequence.erase(sequence.begin()+(i+1));
}
i++;

if(count>1)
{
return false;}
}

if(count<=1)
{
return true;
}

}

int main()
{
vector<int>arr{1,6,5,8,9};
cout<<almostIncreasingSequence(arr)<<endl;

}
is this the right code?

jeron1 25-Oct-17 10:01am

Does it work?

Member 13277493 25-Oct-17 12:10pm

It works, but some tests are not working correctly.

CPallini 25-Oct-17 12:23pm

Because you always remove the (i+1)^th item. AS I stated you should also try to remove the i^th item.

Member 13277493 25-Oct-17 13:24pm

sorry if my question is stupid but I wrote like this, this added true mark for also one test, I don't fully understand what happens with the array
bool almostIncreasingSequence(std::vector<int> sequence)
{
int count=0;
int i=0;

while(i<(sequence.size()-1))
{

if(sequence[i]>sequence[i+1])
{

sequence.erase(sequence.begin()+(i+1));
count++;

}
if(sequence[i]==sequence[i+1])
{
sequence.erase(sequence.begin()+i);
count++;
}
i++;

if(count>1)
{
return false;}
}

if(count<=1)
{
return true;
}

}