INCRDEC - Editorial

editorial
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23

Why is this code showing WA …it works fine on almost all testcases…Can someone Help out plz

#include<bits/stdc++.h>
using namespace std;

int main(){

int t;
cin >> t;

while(t--){

	int n;
	cin >> n;
	map<int,int> p;
	for(int i=0;i<n;i++){
		int temp;
		cin >> temp;
		p[temp]++;
	}

	bool a = false;
	for(auto it = p.begin();it != p.end();it++){

		if(it->second > 2){
			cout << "NO" << endl;
			a = true;
			break;
		}

		if(it-> second == 2 && (++it) == p.end() ){
			cout << "NO" << endl;
			a = true;
			break;
		}

	}

	if(a){
		continue;
	}else{

		cout << "YES" << endl;

		for(auto it = p.begin(); it != p.end() ;it++ ){

			it->second -= 1;
			cout << it->first << " ";

		}

		auto it = p.end();
		it--;
		for( ;  ;it--){

			if(it->second > 0){
				cout << it->first << " ";
			}

			if(it == p.begin()){
				break;
			}
		}
	}
}

return 0;

}

24

This is my code, please provide testcase where my code goes wrong
https://www.codechef.com/viewsolution/34819485
I use same logic that explained above, but still got WA

25

You have not used endl after printing the sequence

26

Check my java solution. It can help you.

https://www.codechef.com/viewsolution/34806335

27

check this solution
https://www.codechef.com/viewsolution/34806335

28

I have two solution. One is working and other one is not . Can someone tell me the test case where it is getting rejected.
working solution = CodeChef: Practical coding for everyone
not working = CodeChef: Practical coding for everyone

Second soln is also getting tle . Somehow I solved this question in the contest. But it wasted lot of time. If someone can tell me why tle in the second solution, it would be appreciated.

29

https://www.codechef.com/viewsolution/34778934
Luckily My approach Got AC :wink:

30

Could you explain your logic on line 43?
Why are you comparing A[i] == a[i+1]?

31

https://www.codechef.com/viewsolution/34834875
C++ solution with detailed explanation in comments…
Please give it a read…

32

My c++ solution CodeChef: Practical coding for everyone

33

Since n can 2*10^3 at max, a simple hash algorithm will pass.
https://www.codechef.com/viewsolution/34794934

34

Bro, as you are using insert and erase function inside for loop that’s why Time complexity of your program is O(N^2) that’swhy it is showing TLE. Try to convert it into O(N*Logn).

1 Like
35

Even i am getting AC in 2nd subtask and WA in the first one
pls find the error

#include <bits/stdc++.h>
#include
using namespace std;

int main() {
int t;
cin>>t;
while(t–){
int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++){
cin>>a[i];
}
sort(a,a+n);
int c=0;
for(int i=0;i<n-1;i++){
if(a[i]==a[i+1]){
c++;
break;
}
}
if(c==0){
cout<<“YES”<<endl;
for(int i=0;i<n;i++){
cout<<a[i]<<" “;
}
cout<<endl;
}
else{
c=0;
if(a[n-2]==a[n-1])
cout<<“NO”<<endl;
else{
int b[n],j=0;
for(int i=0;i<n-1;i++){
if(a[i]==a[i+1]){
b[j]=i+1;
j++;
c++;
}
else c=0;
if(c>=2)
break;
}
int x=j-1;
if(c>=2)
cout<<“NO”<<endl;
else{
cout<<“YES”<<endl;
j=0;
for(int i=0;i<n;i++){
if(i!=b[j])
cout<<a[i]<<” “;
else j++;
}
for(j=x;j>=0;j–){
cout<<a[b[j]]<<” ";
}
cout<<endl;
}
}
}

}

return 0;

}

36

TlE only fisrt case passing
https://www.codechef.com/viewsolution/34837889

37

Do not print each element of the permuted sequence individually.
Try to store the elements of the permuted sequence into string builder object and then print it.
https://www.codechef.com/viewsolution/34838305

2 Likes
38

https://www.codechef.com/viewsolution/34843553
Could anyone tell me why its giving worng answer
The logic is same as the editorial. i cannot find any mistake in here

40

//can anyone tell me the mistake in this code.it works fine for given test case but getting WA

#include
#include
#include
using namespace std;
int main(){

int t;
cin>>t;

while(t--){
    int n;
    cin>>n;

    int arr[n];
    for(int i =0 ; i<n ; i++)
        cin>>arr[i];

    int flag = 1;
    int prev = INT_MAX;
    
    int count = 1;
    sort(arr , arr + n);
    for(int i = 0 ; i<n ; i++){
       if(count > 2){
            cout<<"NO"<<endl;
            flag = 0;
            break;
       }
       else{
            if(prev == arr[i]){
                count++;
                
           }
           else{
                count = 1;
            }
        }
        prev = arr[i];
    }
    if(arr[n-1] == arr[n-2] && flag){
        cout<<"NO"<<endl;
        flag = 0;
        break;
    }

    if(flag){
        int p = INT_MAX;
        cout<<"YES"<<endl;
        for(int i = 0 ; i<n; i++){
            if(p != arr[i]){
                p = arr[i];
                cout<<arr[i]<<" ";
                arr[i] = -1;
            }
            
        }
        sort(arr,arr+n , greater<int>());
        for(int i = 0 ; i<n ; i++){
            if(arr[i] != -1)
                cout<<arr[i]<<" ";
        }

        cout<<endl;
    }
}

}

1 Like
41

Hello. Can anyone please tell me what’s wrong in my solution? It passes all the given test cases but gives WA for both subtasks.
https://www.codechef.com/viewsolution/34848832

42

Nice approach but it can be way simpler. cheers !!

43

it will check whether three elements are equal or not