11349 - Symmetric Matrix

[sharath]

Surprisingly executing the same code in my windows XP PC gives the proper output and I think it is because of fflush(stdin) statement which is platform dependent. So for the platforms not supporting fflush (stdin) the input logic fails and hence the code. Thanks for pointing it out, I changed the input logic and got AC

[mf]

fflush(stdin) is a no-op in every sane programming environment, because fflush is only supposed to flush stream's *output* buffers.

But Microsoft's runtime library went totally nuts and defines it as discarding stream's input buffer as well. Well, usually it is a mistake to want to discard input buffers – or you'll risk throwing away the stuff you care about. Remember that the judge gives you the whole input at once from a file. Nobody's sitting there and typing the input line-by-line, as you might do in your own environment.

[r2ro]

This problem is not difficult, but I cannot seem to get ACC. (WA always).

Here's my code, kindly check it out?

Code: Select all

Accepted. I was forgetting the '.' at the end xD

[plamplam]

Ahh....very tricky and very nice The range of the integers are 2^32 <= Mij <= 2^32, so you must use long long int. I got Wrong Answer twice because of this . And remember to include a '.' at the end of all your results. Also remember that if any of the numbers is negative, then the matrix is non-symmetrical. For example:

Code: Select all

1
N = 3
-5 -1 -3
-2 0 -2
-3 -1 -5

The result for this one is non-symmetrical.

[shuvokr]

Remove after AC

[brianfry713]

Input:

Code: Select all

1
n = 1
-1

Correct output:

Code: Select all

Test #1: Non-symmetric.

[ahmed mohamed said]

#include <iostream>
using namespace std;
int main()
{
bool x = true;
int testcases;
cin>>testcases;
for(int t=1 ; t<=testcases; t++)
{
char Nu , eq ;
int N ;
cin>>Nu; cin>>eq ;cin>>N;
long** matrix = new long*[N];
for(int k = 0 ; k<N; k++)
matrix[k] = new long[N];
for(int i=0 ; i<N ; i++)
{
for (int j=0 ; j<N ; j++)
{
cin>>matrix[j];
}
}
for(int i=0 ; i<N ; i++)
{
for(int j=0 ; j<N ; j++)
{
if (matrix[j] < 0 )
{
x =false ;
break;
}
}
if(x == false)
break;
}
if (x==false)
{
cout<<"Test #"<<t<<": Non-symmetric."<<endl;
}
else
{

for(int i=0 ; i<N ; i++)
{
for(int j=0 ; j<N; j++)
{
if(matrix[j] == matrix[N-(i+1)][N-(j+1)])
x=true;
else
{
x=false;
break;
}
}
if(x == false)
break;
}
if(x)
cout<<"Test #"<<t<<": Symmetric."<<endl;
else
cout<<"Test #"<<t<<": Non-symmetric."<<endl;
}
for(int i=0 ; i<N ; i++)
delete []matrix;
delete []matrix;
}
return 0;
}

[brianfry713]

Use long long.

[uDebug]

Here's some input I found useful during testing / debugging.

Input:

Code: Select all

8
N = 3  
5 1 3
2 -5 2
3 1 5
N = 4 
4294967296 87 1 3
2 88 2 21
21 2 88 2
3 1 87 4294967296
N = 1 
-1
N = 1 
66
N = 2 
4 5
5 4
N = 5 
5 1 3 2 99
2 5 2 1 2
987 77 66 78 987
2 1 2 5 2
99 2 3 1 5
N = 5 
5 1 3 2 99
2 5 2 1 2
987 77 66 77 987
2 1 2 5 2
99 2 3 1 5
N = 5 
5 1 3 2 99
2 5 2 1 2
987 77 -66 78 987
2 1 2 5 2
99 2 3 1 5

AC Output:

Code: Select all

Test #1: Non-symmetric.
Test #2: Symmetric.
Test #3: Non-symmetric.
Test #4: Symmetric.
Test #5: Symmetric.
Test #6: Non-symmetric.
Test #7: Symmetric.
Test #8: Non-symmetric.

[jokerz]

@ v1n1t
why case 6 is non-symmetric???

[jokerz]

Here's some input I found useful during testing / debugging.

Input:

Code: Select all

8
N = 3  
5 1 3
2 -5 2
3 1 5
N = 4 
4294967296 87 1 3
2 88 2 21
21 2 88 2
3 1 87 4294967296
N = 1 
-1
N = 1 
66
N = 2 
4 5
5 4
N = 5 
5 1 3 2 99
2 5 2 1 2
987 77 66 78 987
2 1 2 5 2
99 2 3 1 5
N = 5 
5 1 3 2 99
2 5 2 1 2
987 77 66 77 987
2 1 2 5 2
99 2 3 1 5
N = 5 
5 1 3 2 99
2 5 2 1 2
987 77 -66 78 987
2 1 2 5 2
99 2 3 1 5

AC Output:

Code: Select all

Test #1: Non-symmetric.
Test #2: Symmetric.
Test #3: Non-symmetric.
Test #4: Symmetric.
Test #5: Symmetric.
Test #6: Non-symmetric.
Test #7: Symmetric.
Test #8: Non-symmetric.

why case 6 is non symmetric???

[brianfry713]

In the third row 77 != 78

[uDebug]

why case 6 is non symmetric???

Repeating your question doesn't make someone answer it quicker.

In the third row 77 != 78

Thank you for helping make things clear.

[Helaluddin_brur]

removed after ac