Thank you very much bro.
1 Like
Can you please help me tell why my solution is not working.
Can anyone tell me what’s wrong with my backtrack code? It is quite readable.
My submission
Thank you in advance.
That’s not a link to your solution!
Here is a link to your solution.
This also fails the testcase:
1
10 2
-1 -1 -1 -1 -1 2 -1 -1 -1 2
There’s an out-of-bounds access at the line:
if(arr[curr]==arr[curr-1] && curr>0) return false;
given the testcase:
1
43 2
-1 -1 -1 -1 -1 2 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
which is probably interfering with the results. (This is likely not the only problem).
This fails the testcase:
1
10 2
-1 -1 -1 -1 -1 2 -1 -1 -1 2
add the following in your code
import sys
sys.setrecursionlimit(10**9)
This question is a classic example of Implementation being the hardest part.
https://www.codechef.com/viewsolution/26188055
Please help out with some cases. My solution gets only 70
Yours also fails the testcase:
1
10 2
-1 -1 -1 -1 -1 2 -1 -1 -1 2
Edit:
You also have a lot of compiler warnings which you should verify aren’t causing a problem:
Compiler warnings
rashu1999-TRIP2.cpp:50:28: warning: using the result of an assignment as a condition without parentheses [-Wparentheses]
else if(no = -1 && arr[1] == -1)
~~~^~~~~~~~~~~~~~~~~~~~
rashu1999-TRIP2.cpp:50:28: note: place parentheses around the assignment to silence this warning
else if(no = -1 && arr[1] == -1)
^
( )
rashu1999-TRIP2.cpp:50:28: note: use '==' to turn this assignment into an equality comparison
else if(no = -1 && arr[1] == -1)
^
==
rashu1999-TRIP2.cpp:101:35: warning: '&&' within '||' [-Wlogical-op-parentheses]
if(l == 1 && r == 1 || l == 1 && r>2 || l>2 && r == 1)
~~~~~~~^~~~~~~~~ ~~
rashu1999-TRIP2.cpp:101:35: note: place parentheses around the '&&' expression to silence this warning
if(l == 1 && r == 1 || l == 1 && r>2 || l>2 && r == 1)
^
( )
rashu1999-TRIP2.cpp:101:55: warning: '&&' within '||' [-Wlogical-op-parentheses]
if(l == 1 && r == 1 || l == 1 && r>2 || l>2 && r == 1)
~~ ~~~~~~~^~~~~~
rashu1999-TRIP2.cpp:101:55: note: place parentheses around the '&&' expression to silence this warning
if(l == 1 && r == 1 || l == 1 && r>2 || l>2 && r == 1)
^
( )
rashu1999-TRIP2.cpp:101:69: warning: '&&' within '||' [-Wlogical-op-parentheses]
if(l == 1 && r == 1 || l == 1 && r>2 || l>2 && r == 1)
~~ ~~~~^~~~~~~~~
rashu1999-TRIP2.cpp:101:69: note: place parentheses around the '&&' expression to silence this warning
if(l == 1 && r == 1 || l == 1 && r>2 || l>2 && r == 1)
^
( )
rashu1999-TRIP2.cpp:104:40: warning: '&&' within '||' [-Wlogical-op-parentheses]
else if(l == 2 && r == 1 || l==1 && r==2)
~~~~~~~^~~~~~~~~ ~~
rashu1999-TRIP2.cpp:104:40: note: place parentheses around the '&&' expression to silence this warning
else if(l == 2 && r == 1 || l==1 && r==2)
^
( )
rashu1999-TRIP2.cpp:104:58: warning: '&&' within '||' [-Wlogical-op-parentheses]
else if(l == 2 && r == 1 || l==1 && r==2)
~~ ~~~~~^~~~~~~
rashu1999-TRIP2.cpp:104:58: note: place parentheses around the '&&' expression to silence this warning
else if(l == 2 && r == 1 || l==1 && r==2)
I have corrected that still it fails. This is my updated solution.
Please check this
https://www.codechef.com/viewsolution/26224804
This appears to give no output for the testcase:
1
2 2
2 1
Please help me in this problem.
I use algo like this:
count -1 while input
1.) if n = 1,
-> if a[0] = -1 print YES/n k
->else print YES\n cout<<a[0]
2.) else if(count == 0)
->print array as it is
3.) First detect the no -1.
-> if i> 0 and i<n-1, then
…I took var sum = a[i-1]+a[i+1] & var avg = sum/2;
…If sum == 0
a[i]=2; count–
…else if(sum <=k)
a[i]=sum; count–
…else if(sum > k)
if(avg == a[i-1])
if(a[i-1]-1 > 0)
c–; a[i] = avg-1;
else if(avg == a[i+1]){
if(a[i+1]-1 > 0)
a[i] = avg-1; c–;
else
a[i] = avg; c–;
-> else If it is at i = 0, then
if(a[i] != -1)
…if a[i+1]+1<=k then a[i] = a[i+1]+1; count–
…else if a[i+1]-1>0 then a[i] = a[i+1]-1 count–
else
…a[i]=k; count–
-> else If it is at i = n-1, then
if(a[i] != -1)
…if a[i-1]+1<=k then a[i] = a[i-1]+1 count–
…else if a[i-1]-1>0 then a[i] = a[i-1]-1 count–
else
…a[i]=k; count–
->if count != 0
…cout<<“NO”
else
…print YES and array
HELP IN IT
Hey
Please help me finding the problem in my code
Thank you 
#include <bits/stdc++.h>
using namespace std;
int main() {
int t, l, r;
cin>>t;
while(t–)
{
int n, k, temp;
cin>>n>>k;
vector<int> arr;
for(int i = 0; i<n; i++)
{
cin>>temp;
arr.push_back(temp);
}
if(n<1)
cout<<"NO\n";
else if(n == 1)
{
cout<<"YES\n";
if(arr[0] == -1)
cout<<1<<"\n";
else
cout<<arr[0]<<"\n";
}
else
{
if(k == 2)
{
int pos = -1, no = -1;
for(int i = 0; i<n; i++)
{
if(arr[i]!= -1)
{
pos = i;
no = arr[i];
break;
}
}
if((pos != -1) && (pos % 2 == 0) && (arr[0] == -1))
{
arr[0] = no;
}
else if((no != -1) && (arr[1] == -1))
arr[1] = no;
}
bool chk = true;
// cout<<chk<<"\n";
if(n == 2)
{
if((arr[0]!=-1) && (arr[0] == arr[1]))
{
cout<<"NO\n";
chk = false;
}
// else
// {
// }
}
if(arr[0] == -1)
{
r = arr[1];
if(r == 1)
arr[0] = 2;
else
arr[0] = 1;
}
// cout<<chk;
for(int i=1; i<n-1; i++)
{
if(arr[i] != -1)
{
if((arr[i-1] == arr[i]) || (arr[i] == arr[i+1]))
{
cout<<"NO\n";
chk = false;
break;
}
}
else if(arr[i] == -1)
{
l = arr[i-1];
r = arr[i+1];
if(r == -1)
{
if(l == 1)
arr[i] = 2;
else
arr[i] = 1;
}
else
{
if(((l == 1) && (r == 1)) || ((l == 1) && (r>2)) || ((l>2) && (r == 1)))
arr[i] = 2;
else if(((l == 2) && (r == 1)) || ((l==1) && (r==2)))
{
if(k>2)
arr[i] = 3;
else
{
cout<<"NO\n";
chk = false;
break;
}
}
else
arr[i] = 1;
}
}
}
// cout<<chk;
if(chk)
{
if(arr[n-1] == -1)
{
l = arr[n-2];
if(l == 1)
arr[n-1] = 2;
else
arr[n-1] = 1;
}
cout<<"YES\n";
for(int i=0; i<n; i++)
cout<<arr[i]<<" ";
cout<<"\n";
}
}
}
}
Please format it or link to a solution - the forum software has manged it and it won’t compile 
Edit:
It’s now failing for the testcase:
1
5 2
2 -1 -1 -1 -1
Your code produces no output for the testcase:
1
3 2
-1 -1 -1
Got the mistake. Thanks for help. Tricky cases and silly mistakes 
1 Like
Nice one - happy to help 