OJ Board

Hi! Some time ago I've solved problem 10104 (Euclid Problem) by using Euclid's Extended Algorithm. The thing is that I didn't even considered the additional restrictions (|x|+|y| = minimum, x<= y if there's a tie). Recently I re-read the problem and come to wonder if the algorithm always gives a pai...

Hi! double floor(double x): rounds x down to the nearest integer. double ceil(double x): rounds x up to the nearest integer. double round(double x): rounds x to the nearest integer, but round halfway cases away from zero. double trunc(double x): round x to the nearest integer not larger in absolute ...

Hi! It seems that the easiest way to change from floats to ints is by casting, but this may lead to errors. In Pascal I use round, but C lacks of a similar function. I'm currently using this function but I want to know if there's a better way. long float_to_int(double fX) { return((fX -((long) fX) <...

Hi! Here's my code. Hope it helps! int odd(long x) { return ((x & 0x0001)!= 0); } void matrix_multiply(long aiMatrix1[][2], long aiMatrix2[][2], long aiResult[][2]) { long aiTemp[2][2]; aiTemp[0][0]= aiMatrix1[0][0]*aiMatrix2[0][0] + aiMatrix1[0][1]*aiMatrix2[1][0]; aiTemp[0][1]= aiMatrix1[0][0]...

Hi! Thanks for your answer. I participed in some ICPC regionals, but as me and my coach were new at this, we learned as we went. Now I'm a coach (along with my former coach) of the OMI (Mexico Informatics Olympiad) at my state. My coach still trains teams for the ICPC (and I might join him). As what...

Hi! Which are good topics when training for IOI and ICPC? What topics might differ when training for each one? What "strategy" might differ when training for each one? Also, any good problem(s) for divide-and-conquer? (that don't use a common algorithm, such as binary search or convex hull...

Here I define the precision. Const error= 10e-7; Here I define a point, x,y,z are coordinates, m is the slope (using 0,0 as the other point) and r is used to indicate if it's visible (1= visible, 0= not visible). Type punto= record m: extended; r,x,y,z: longint; end; I declare variables, c is for co...

I keep getting WA. I think it might be because of precision errors (I'm not very used to geometric problems). Any help appreciated. Const error= 10e-7; Type punto= record m: extended; r,x,y,z: longint; end; Var c,i,n,t: longint; p: array [1..100000] of punto; Function menor_m(a,b: punto): boolean; b...

After several WA I discovered some thing that might be helpful: There are no inputs like the above 3 c b a 6 a-b: 24-19 25-24 37-23 40-11 42-12 b-a: 25-19 25-20 25-24 11-25 11-29 b-c: 25-24 25-20 25-23 25-12 25-11 c-a: 25-26 25-27 27-23 30-11 35-12 a-c: 25-19 25-20 25-23 c-b: 25-19 25-20 25-23 0 Fir...

It's wierd to get an answer after almost two years! Anyway, very good answer. Thanks!

PS: I think you can change your readln(s) for only readln and it would still work (and you wouldn't need the string).

Thanks a lot! I would never thought of that!

Could someone check my code? Thanks!

Can someone check my code? [pascal] Var c,f,i,l,n,p,q,t: byte; a: array [1..100,1..100] of boolean; Procedure visita(v: byte); var j: byte; begin for j:= 1 to n do if not a[v,j] then begin a[v,j]:= true; Inc(t); visita(j); end; if (t>l) or ((t=l) and (v<f)) then begin l:= t; f:= v; end; Dec(t); end;...

Thanks a lot! I finally got AC!

The funny thing is that I got AC on the other Golbach problem and it had the same mistake.


By the way, my name is Pier, not Per. (I think you might confused my name with Per Austrin, or maybe it's just a typo).

Could some give me some test, please?