TWOGRS - Editorial

vibhoragrawal · September 23, 2019, 5:35am

Can anyone please suggest me the mistake in my program. As, the testcases I am able to think gives the correct output, but instead it is showing wrong answer.
I will be very much thankful to the one who helps me…

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;

int main(){
int t;
cin>>t;
while(t–){
ll a, b, c;
cin>>a>>b>>c;
ll sum = a1 + b2 + c*3;
if(sum%2!=0){
cout<<“NO”<<endl;
}
else if(a==0&&b==0&&c==0){
cout<<“NO”<<endl;
}
else if(c%2==0){
if(a%2!=0){
cout<<“NO”<<endl;
}else{
if(b%2!=0){
if(a<2){
cout<<“NO”<<endl;
}else{
cout<<“YES”<<endl;
}
}else{
cout<<“YES”<<endl;
}
}
}else{
if(a%2==0){
cout<<“NO”<<endl;
}else{
if(b%2==0){
if(a>=3){
cout<<“YES”<<endl;
}else{
cout<<“NO”<<endl;
}
}else{
cout<<“YES”<<endl;
}
}
}
}

return 0;

}

Also please tell me the case for this it doesn’t work correctly…

anon55659401 · September 23, 2019, 5:40am

Check my editorial for this problem here :- Unofficial editorial-TWOGRS

siri_99 · September 23, 2019, 5:56am

can anyone please tell me what is the mistake in my code.
#include<stdio.h>
int main()
{
int t,T;
long int A,B,C;
long long int sum1,sum2;
scanf("%d",&T);
for(t=0;t<T;t++)
{
scanf("%ld %ld %ld",&A,&B,&C);
sum1=sum2=A1+B2+C3;
if(sum1%2!=0)
printf(“NO\n”);
else
{
sum1=sum1/2;
while(sum1>0)
{
if(sum1==1 && A>0)
{
sum1-=1;
A-=1;
}
else if(sum1==2 && B>0)
{
sum1-=2;
B-=1;
}
else if(sum1==3 && C>0)
{
sum1-=3;
C-=1;
}
else
{
if(A>0)
{
sum1-=1;
A-=1;
}
else if(B>0)
{
sum1-=2;
B-=1;
}
else if(C>0)
{
sum1-=3;
C-=1;
}
else
break;
}
}
sum2=sum2/2;
if(sum1==0)
{
if((1A+2B+3C) == sum2)
printf(“YES\n”);
else
printf(“NO\n”);
}
else
printf(“NO\n”);
}
}
return 0;
}

nayanbhakat · September 23, 2019, 6:07am

How to reach the conclusion that 7,4,4 need to be used to lower the constraints without affecting the solution. Plz reply!!

shashi_23 · September 23, 2019, 7:21am

how fix functions has been evaluated and what this function is actually doing…Can somebody please help @taran_1407

ukt1997 · September 23, 2019, 9:01am

I am also trying same approach @nihaljain , Everyting seems fine yet getting WA , can someone check and explain what I am doing wrong.My Solution

shardic · September 23, 2019, 10:07am

Because it’s simple bruteforce! xD

rude009 · September 23, 2019, 10:22am

Not just that, he found out that subtracting two from any of the A, B, C does not change the answer to be printed.

anon79977241 · September 23, 2019, 10:32am

can any one tell me What wrong in my approach ?

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

int main() {
// your code goes here
//freopen(“input.txt”,“r”,stdin);
int t;
cin>>t;
while(t–){
int a,b,c;
cin>>a>>b>>c;
long long sum1 = 0;
long long sum2 = 0;

    if(c%2 == 1){
        sum1 += 3;
        c--;
    }
        int x = c / 2;
        sum1 += 3*x;
        sum2 += 3*x;
        if(b%2 != 0){
            if(sum1<sum2){
                sum1 += 2;
            }else
                sum2 += 2;
            b--;
        }
        x = b / 2;
        sum1 += 2*x;
        sum2 += 2*x;
        long long diff = sum1 - sum2;
        if(a >= diff){
            a = a - diff;
            if(a%2 == 0){
            cout<<"Yes"<<endl;
            }else
                cout<<"No"<<endl;
        }else{
            cout<<"No"<<endl;
        }

}
return 0;

}

Thanks!

rudransh_bt · September 23, 2019, 10:58am

Can someone please tell what is wrong in my code?? Thanks

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

int main()
{
    int tc;
    cin>>tc;
    int a,b,c,q1,q2,q3;
    while(tc--)
    {
        cin>>a>>b>>c;
        long int sum = a + b*2 + c*3;
        if(sum%2==1)
            cout<<"NO\n";
        else
        {
            sum=sum/2;
            q3=sum/3;
            sum = sum - min(q3,c)*3;

            q2=sum/2;
            sum = sum - min(q2,b)*2;

            q1=sum/1;
            sum = sum - min(q1,a);

            if(sum>0)
                cout<<"NO\n";
            else
                cout<<"YES\n";
        }
    }
}

dhruv_gheewala · September 23, 2019, 12:32pm

my approch is also similar to this.and i am getting WA.and i dont know the reason.

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

#define MOD (1000000007)
//Data-type
#define ui unsigned int
#define d(str) cout<<#str<<" : “<<str<<”\n"
#define nl cout<<’\n’
#define fast ios_base::sync_with_stdio(0)
#define mem(a,b) memset(a,b,sizeof(a))
#define arr_sort(a,n) stable_sort(a,a+n)
#define _sort(a) stable_sort(a.begin(),a.end())
#define test int t=0,i=0,j=0;
cin>>t;
while(t–)
#define min(a,b) ((a)>(b)?(b):(a))

int main()
{
fast;
int a,b,c,sum;
test
{
cin>>a>>b>>c;
sum=a+2b+3c;
if(sum&1)
cout<<“NO”;
else
{
int x,k=sum;

        k/=2;
        x=k/3;
        k=k-3*min(x,c);

        x=k/2;
        k=k-2*min(x,b);

        if(k <= a)
            cout<<"YES";
        else
            cout<<"NO";
    }
    nl;
}
return 0;

}

smile_forever · September 23, 2019, 1:16pm

@admin Why this solution accepted?

For case: 0 7 10
This solution provide NO But it should be YES
Given : [0 7 10] => {0, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3}
Group 1 : {2, 2, 3, 3, 3, 3, 3, 3}
Group 2: {2, 2, 2, 2, 2, 3, 3, 3, 3}

Some contestant +rated for this solution, Please check out it. Thanks.

smile_forever · September 23, 2019, 1:57pm

@spd_25 Please check out the following test cases::

Do you need more test cases??

betuyash · September 23, 2019, 2:04pm

How did you reach this solution !? Specifically saying from step 3 to 5.

smile_forever · September 23, 2019, 2:04pm

You should provide the link of your solution or format it correctly.
Just copy and pest your code between ``` and ```

\```
Code here
\```

[Without back slash \]

anon55659401 · September 23, 2019, 2:05pm

Ready my editorial for detailed explanation

smile_forever · September 23, 2019, 2:27pm

Umm,Better explained

Have some similarity with my logic:

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

int main() {
  ios_base::sync_with_stdio(false); cin.tie(NULL);
  ll t; cin >> t;
  while (t--) {
    ll a, b, c; 
    cin >> a >> b >> c;
    if ((a + c) % 2 == 0) {
      if (a > 0 and b > 0 and c > 0)
        cout << "YES" << "\n";
      else if (a + b == 0 or a + c == 0 or b + c == 0) {
        if ((a + b + c) % 2 == 0)
          cout << "YES"<< "\n";
        else
          cout << "NO" << "\n";
      } else if (a == 0 and b > 1) 
        cout << "YES" << "\n";
      else if (b == 0 and a > 1) 
        cout << "YES"<< "\n";
      else if (c == 0)
        cout << "YES"<< "\n";
      else
        cout << "NO" << "\n";
    } else
      cout << "NO" << "\n";
  }
  return 0;
}

lazybyte79 · September 23, 2019, 2:34pm

https://www.codechef.com/viewsolution/26744442
how can these solution pass all the test case o(3*1e9) complexity ??

anshulv8 · September 23, 2019, 3:15pm

s = 1A + 2B + 3C
=> (2-1)A + 2B + (2 + 1)C
=> 2(A +B + C) + (C-A)
NOW
S/2 = (A +B +C) + (C-A)/2
entire problem depends upon weather c-a is even or not
just run a loop that sees if c-a is even then calculate S based upon above equation, i suppose it might work

anon55659401 · September 23, 2019, 3:28pm

Omg…this is some serious stuff here…