It's very funny to read how I tried to solve:

1-st time I forgot to multiply answer by 2 :)
2-nd time I retyped code by forgot to set 'Pascal' (and it was compile error)
3-rd time I forgot 'begin' :)
4-th time I typed task correctly and it was accepted !!!

So, programmers, DO NOT HURRY if you don't want to repeat my funny story :)

Edited by author 10.09.2004 00:28

the difficulty rangering here is absolutely uncorrect and unjust

Edited by author 31.01.2019 04:21

I used template programming to write 3D Fenwick tree and I get "Compiler failed" verdict when compiling with G++ (not "Compilation Error", but "Compiler failed"; no error message). The solution works fine and gets Accepted with Visual Studio and Clang.

I assume it is because of the recursive template operations, but it works when I compile it locally with G++ (using the flags provided on help.aspx?topic=cpp). It also work on other online judges, such as codeforces, which also use mingw g++.

Could I get some insight on this? I'm curious why this happens.

#include <iostream>
using namespace std;
int main() {
    long x, y, c, a, b, MIN, MAX;
    cin >> x >> y >> c;
    if (x + y < c) {
        cout << "Impossible";
        return 0;
    }
    if (x >= c)
        cout << c << " " << 0;
    else if (y >= c)
        cout << 0 << " " << c;
    else{
        if (x < y)
            cout << x << " " << c - x;
        else
            cout << c - y <<  " " << y ;
    }
}

This is my code.
#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int n,a,k=0;
    cin>>n;
    vector <int> v;
    vector <int> sum;
    vector <int> index;
    for(int i=0; i<n; i++)
    {
        cin>>a;
        v.push_back(a);
    }
    for(int i=1; i<n-1; i++)
    {
        sum.push_back(v[i-1]+v[i]+v[i+1]);
        index.push_back(i);
    }
    int max=sum[0];
    for(int i=1; i<n; i++)
    {
        if(sum[i]>max) {max=sum[i]; k=i;}
    }
    cout<<max<<" "<<index[k]+1;
    system("pause");
    return 0;
}

just be patient while making precalculation :)

Жеванный крот, одна халтура! Мало того что английский перевод кривой как рог барана, так ещё и проверяющая система хромает!

Отправляем на проверку:
Var
s, s1: ansistring;
a, b: byte;

Begin
readln(s, s1); val(s[length(s)], b);

End.

Получаем вполне обоснованный WA1.
Теперь дополним:
Var
s, s1: ansistring;
a, b: byte;

Begin
readln(s, s1); val(s[length(s)], b);
val(s1[length(s1)], a);

End.

Всё, вселенная дрогнула: "Access violation"... *facepalm*
И всё бы ничего, но подобное происходит уже где-то раз пятый (в разных задачах).
И да, прочитать string целиком, а затем разрезать - выдаёт ту же ошибку AV:
Var
s, s1: ansistring;
i, a, b: byte;

Begin
readln(s); for i:=1 to length(s) do if s[i]:=' ' then begin val(s[i-1], b); val(s[length(s)], a); break; end;

End.

Сделайте уже нормальный ввод!!!!1

Edited by author 01.02.2020 21:32

I recommend you this resource: https://e-maxx.ru/algo/bfs
also you can make a function instead of the lyambda, but I just like lyambdas more.
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
int main() {
    int N;
    cin >> N;
    vector <vector <int>> g(N);
    int h;
    for (int i = 0; i < N; i++) {
        for (;;) {
            cin >> h;
            if (!h)
                break;
            g[i].push_back(h - 1);
        }
    }
    int n = g.size();
    queue<int> q;
    vector<bool> used(n);
    vector<int> d(n);
    int s;
    auto bfs = [&](int start) {
        s = start;
        q.push(s);
        used[s] = true;
        while (!q.empty()) {
            int v = q.front();
            q.pop();
            for (size_t i = 0; i<g[v].size(); ++i) {
                int to = g[v][i];
                if (!used[to]) {
                    used[to] = true;
                    q.push(to);
                    d[to] = d[v] + 1;
                }
            }
        }
    };
    for (int start = 0; start < n; ++start)
        if (!used[start]) {
            bfs(start);
        }
    vector <int> ans;
    for (int i = 0; i < n; i++) {
        if (d[i] % 2 == 0)
            ans.push_back(i + 1);
    }
    int size = ans.size();
    cout << size << '\n';
    for (int i = 0; i < size; i++)
        cout << ans[i] << " ";
}

Edited by author 26.01.2019 22:53

Edited by author 30.01.2019 03:16

Edited by author 01.02.2020 21:31

using System;
using System.Linq;

namespace Csharp_1567
{
    class Program
    {
        static void Main(string[] args)
        {
            string str1 = Console.ReadLine();
            uint sum = 0;
            int lin = (from n in str1
                       select n).Count();
            for (int i =0;i<lin;i++)
            {
                if (str1[i] == 'a' || str1[i] == 'd' || str1[i] == 'g' || str1[i] == 'j' || str1[i] == 'm' || str1[i] == 'p' || str1[i] == 's' || str1[i] == 'v' || str1[i] == 'y' || str1[i] == '_' || str1[i] == '.' || str1[i] == ' ')
                {
                    sum += 1;
                    continue;
                }
                else if (str1[i] == 'b' || str1[i] == 'e' || str1[i] == 'h' || str1[i] == 'k' || str1[i] == 'n' || str1[i] == 'q' || str1[i] == 't' || str1[i] == 'w' || str1[i] == 'z' || str1[i] == ',')
                {
                    sum += 2;
                    continue;
                }
                else sum += 3;
            }
            Console.WriteLine(sum);
        }
    }
}

I got WA 1, but when I test this code myself, I always get a correct answer. What's wrong?

#include <iostream>
using namespace std;

int main()
{
    char speech[1001];
    cin.getline(speech, 1001);
    int cost = 0;
    for (int i = 0; i < 1001; i++)
    {
        switch (speech[i])
        {
        case 'a': case 'd': case 'g': case 'j': case 'm': case 'p': case 's': case 'v': case 'y': case '.': case ' ':
            cost += 1;
            break;
        case 'b': case 'e': case 'h': case 'k': case 'n': case 'q': case 't': case 'w': case 'z': case ',':
            cost += 2;
            break;
        case 'c': case 'f': case 'i': case 'l': case 'o': case 'r': case 'u': case 'x': case '!':
            cost += 3;
            break;

        }
    }
    cout << cost << endl;

    return 0;
}

Edited by author 29.08.2018 19:40

https://umath.ru/theory/priznak-delimosti-na-7/

s = 0
k = 1
x = input()
while len(x) > 3:
    s += int(x[-3:]) * k
    k *= -1
    x = x[:-3]
s += int(x) * k
print(s % 7)

Edited by author 25.01.2019 02:16

I didn't do anything for 'arbitary' sequence. But my solution got accepted.Can anybody help me clear this doubt?

Edited by author 22.01.2019 18:38

Edited by author 09.03.2021 22:26

10
6
1 2 even
1 1 even
3 4 odd
5 6 even
1 6 even
7 10 odd

i think the answer of this data should be 1,but my program answer is 4 but it return an accepted!

sort(a + 1, a + 1 + n);
  reverse(a + 1, a + 1 + n);

  for(int i = 1; i <= n; i++){
    if(sum1 > sum2){
      sum2 += a[i];
    }
    else{
      sum1 += a[i];
    }
  }

  cout << abs(sum1 - sum2);

If you write on c++ you can do this:

char dot;
unsigned int x,ip;

ip = 0;

for (int i = 24; i >= 8; i -= 8) {
  cin >> x >> dot;
  x <<= i;
  ip |= x;
}
cin >> x;
ip |= x;
------------------
Now you have ip, same you can read mask.

Edited by author 21.01.2019 14:50

Edited by author 21.01.2019 14:52