const int MaxLength = 30;
const int Lines = 8;
const int MaxStation = 15;
const int Stations[Lines] = {13, 10, 11, 12, 9, 14, 15, 13};
const char Line[Lines][MaxStation][MaxLength + 1] = {
    {"7_klyuchey", "Sortirovochnaya", "China_town", "Zarechny", "City", "1905_year_square", "Kuybyshevskaya",
        "Sibirskaya", "Siniye_kamni", "Lechebnaya", "Varshavskaya", "Kompressornaya", "Koltsovo"},
    {"Zelyony_ostrov", "Tatishchevskaya", "Verh_Isetskaya", "Kommunarov_square", "1905_year_square",
        "Teatralnaya", "Vostochnaya", "Vtuzgorodok", "Kamennye_palatki", "University"},
    {"MEGA", "Metallurgov", "Kraulya", "Central_stadium", "Moskovskaya", "1905_year_square",
        "Shevchenko", "Pionerskaya", "Turbinnaya", "Elmash", "Taganskaya"},
    {"Akademicheskaya", "Yugo_zapadnaya", "Volgogradskaya", "Posadskaya", "Geologicheskaya", "Teatralnaya",
        "Gagarinskaya", "Komsomolskaya", "Shefskaya", "Ozyornaya", "Italyanskaya", "Kalinovskaya"},
    {"Sovhoznaya", "Voennaya", "Aviatsionnaya", "Dvorets_sporta", "Geologicheskaya",
        "Kuybyshevskaya", "Vostochnaya", "Gagarinskaya", "Vilonovskaya"},
    {"Keramicheskaya", "Vtorchermet", "Samolyotnaya", "Botanicheskaya", "Parkovaya", "Mayakovskaya",
        "Oborony_square", "Kuybyshevskaya", "Teatralnaya", "Shevchenko", "Uralskaya", "Zvezda",
        "I_Pyatiletki_square", "Pobedy"},
    {"Himmash", "Nizhne_Isetskaya", "Uktusskie_Gory", "Shcherbakovskaya", "Botanicheskaya", "Chkalovskaya",
        "Bazhovskaya", "Geologicheskaya", "1905_year_square", "Dinamo", "Uralskaya", "Mashinostroiteley",
        "Uralmash", "Prospekt_Kosmonavtov", "Bakinskih_Komissarov"},
    {"Moskovskaya", "Kommunarov_square", "City", "Uralskaya", "Pionerskaya", "Gagarinskaya", "Vtuzgorodok",
        "Sibirskaya", "Oborony_square", "Bazhovskaya", "Dvorets_sporta", "Posadskaya", "Moskovskaya"}
};

Check how you restore the answer. I had the right price , but it brought out fewer dishes than necessary

Can anyone say, what is wrong in my solution?

public class T1779 {
    public static void main(String[] args) throws IOException {
        BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
        PrintWriter out=new PrintWriter(System.out);
        int n=Integer.parseInt(in.readLine());
        int sum=0;
        for(int i=0; i<n/2; i++){
            for(int j=n-i-1; j<n; j++){
                if(i!=j){
                    out.println((i+1)+" "+(j+1));
                    sum++;
                }
            }
        }
        System.out.println(sum);
        out.close();

    }
}

Very good opportunity to apply Gosper's hack trick.

m is number of different colors in the input.

Then iterate through all subsets of size k of m.

I was getting wa6 because the salary[0] not equal to 0

This test case helped me.
6
1 2
2 4
4 5
5 6
BLOOD
3
5

Answer: 0

What data it is?

No need to use simplex alg.
Simple brute force linear programming done in O( Choose(10,4) * 4^3 ) time

The 2nd test on the site does not pass, everything works for me, what should I do?

try this test:
input:
1
2
0 0

output:
NO

because for this sentences in the problem:
"exactly one child has confessed the he (or she) had broken the cup".

I dont notice to this and get WA#2.
sorry for my poor english.

GOOD LUCK!

Edited by author 15.11.2010 23:48

The probable cause of the error is the use of a floating point variable for computing of value a. Any floating point types have limited precision, and looks like some times it is not enough. Consider to use some integer types instead.

pleace

it helped me to pass WA#13

3
1 0 60
12:00
2 1430 45
23:00 0:00

got AC

possible answer 1 or 2

If you search for the id "A216264" on oeis.org, you would find a table of a(n), n=1..60.
One interesting thing is that the site said that it was Mikhail Rubinchik who calculated a(26) to a(60), which happened to be out of the brute-force range. What is really disappointing is that in this problem, n may be 61, I think it's that guys's trick to play with us. Another interesting fact is that this guy also invented and introduced the Palindromic Tree. So, I deduce that the solution to this problem is somehow related to this data structure.

Edited by author 03.04.2016 12:56

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        int c = 0;
        Scanner n = new Scanner(System.in);
        int f = n.nextInt();
        n.close();
        if (f > 0)
        {
            for (int i = 1; i <= f; i++)
                c += i;
            System.out.println(c);
        }
        else if (f <= 0)
        {
            for (int i = f; i <= 1; i++)
                c += i;
            System.out.println(c);
        }

    }
}

#include <iostream>
using namespace std;

int sum(int a) {
    return ((1 + a)/2)*a;
}

int main () {
    int a;

    cin >> a;

    if (a > 0) cout << sum(a);
    else if (a < 0) cout << sum(abs(a)) * -1 + 1;
    else cout << 0;

    return 0;
}

If the i’th student will let the j’th student stand behind him in a line, this is !!!NOT!!! means that the j’th student will let the i’th student too.