i use gauss with choice of maximum element in columns... type is double... to get the answer i had to
ceil(100000*x)/100000;
got WA 5.

Could anyone explain, what's the trick?

for i:=1 to N do A[1,i]:=A[1,i]+A[2,i];
or
for i:=1 to N do A[1,i]:=x*A[1,i]; //x<>0
or
for i:=1 to N do A[1,i]:=x*A[1,i]+y*A[2,i]; //x<>0

think about.

I choose minimal by absolute value element for a[i][i]. Then I perform
a[j][k] -= a[i][k] * (a[j][i] / a[i][i])
this way it gives AC.

Edited by author 25.07.2008 19:40