print(int(input())%7)

in python: -5 % 7 == 2
in c++: -5 % 7 == -5

print(int(input()) % 7)

a = int(input())
c= a//7
d=c*7
print(a-d)

I got my code running due to the solutions posted.. But i want to understand the logic behind the division.. Any one?

#include<bits/stdc++.h>

using namespace std;

int main(){
    unsigned long long int n;
    try{
        cin >> n;
        cout << n%7 << endl;
    }catch(exception e){
        cout << 1 << endl;
    }
    return 0;
}

#include <stdio.h>
int main() {
unsigned long long int a;
scanf("%llu", &a);
if (a/7!=0)
printf("%llu\n", a%7);
else if (a < 7)
printf("%d\n", a); }

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

компилятор visual studio 2010 - 1wa
c++11                          -4wa
c++14                          -4wa
КАК???!!!

Just use it to solve this problem.

del

Edited by author 06.01.2015 21:37

var a:array[1..20] of integer;
n,n1:string;
x,k,i,s,code:integer;
begin
read(n);
x:=length(n);
k:=x div 3;
if x mod 3>0 then k:=k+1;
for i:=1 to k do begin
n1:=copy(n,x-3*i+1,3);
val(n1,k,code);
a[i]:=k;
delete(n,x-2*i,3);
end;
k:=x div 3;
if x mod 3>0 then k:=k+1;
if k div 2=0 then begin
a[1]:=-1*a[1];
a[3]:=-1*a[3];
a[5]:=-1*a[5];
a[7]:=-1*a[7];
a[9]:=-1*a[9];
a[11]:=-1*a[11];
a[13]:=-1*a[13];
a[15]:=-1*a[15];
a[17]:=-1*a[17];
end
else begin
a[2]:=-1*a[2];
a[4]:=-1*a[4];
a[6]:=-1*a[6];
a[8]:=-1*a[8];
a[10]:=-1*a[10];
a[12]:=-1*a[12];
a[14]:=-1*a[14];
a[16]:=-1*a[16];
end;
for i:=1 to 17 do
s:=s+a[i];
write(abs(s mod 7));
end.

what's that means?
Output limit exceeded.

Dear Java Coders, you will solve this problem so easy, if you know what is BigInteger means.

#include <iostream>
#include <math.h>

using namespace std;

int main(){

    double x;
    int i;

    cin >> x;

    x = fmod (x, 7.0);

    printf("%.0f",x);

    system("pause");
    return 0;

}

Edited by author 18.08.2014 21:49

#include <iostream>
using namespace std;


int main()
{
    int k = 0;
    long long int s = 0;
    char num[52];
    int arr[51];
    bool flag = true;
    cin >> num;
    for(int i = 0; flag; i++)
    {
        switch(num[i])
        {
            case '0':
            {
                arr[i] = 0;
                k++;
                break;
            }
            case '1':
            {
                arr[i] = 1;
                k++;
                break;
            }
            case '2':
            {
                arr[i] = 2;
                k++;
                break;
            }
            case '3':
            {
                arr[i] = 3;
                k++;
                break;
            }
            case '4':
            {
                arr[i] = 4;
                k++;
                break;
            }
            case '5':
            {
                arr[i] = 5;
                k++;
                break;
            }
            case '6':
            {
                arr[i] = 6;
                k++;
                break;
            }
            case '7':
            {
                arr[i] = 7;
                k++;
                break;
            }
            case '8':
            {
                arr[i] = 8;
                k++;
                break;
            }
            case '9':
            {
                arr[i] = 9;
                k++;
                break;
            }
            case '\0':
            {
                flag = false;
                break;
            }
        }
    }
    for(int i = k-1; i+1 > 6;)
    {
        s = s + arr[i];
        s = s + arr[i-1]*3;
        s = s + arr[i-2]*2;
        s = s + arr[i-3]*6;
        s = s + arr[i-4]*4;
        s = s + arr[i-5]*5;
        i = i - 6;
        k = k - 6;
    }
    if(k > 0)
    {
        s = s + arr[k-1];
        k--;
    }
    if(k > 0)
    {
        s = s + arr[k-1]*3;
        k--;
    }
    if(k > 0)
    {
        s = s + arr[k-1]*2;
        k--;
    }
    if(k > 0)
    {
        s = s + arr[k-1]*6;
        k--;
    }
    if(k > 0)
    {
        s = s + arr[k-1]*4;
        k--;
    }
    if(k > 0)
    {
        s = s + arr[k-1]*5;
        k--;
    }
    cout << s%7;
    return 0;
}

Edited by author 16.11.2013 14:57

Edited by author 16.11.2013 14:57

I don't understand what's the hint in this problem! I read it and I think this code must be enough to solve that problem in c#:
using System;

namespace ConsoleApplication1
{
    class Program1243
    {
        static void Main()
        {
            ulong n = Convert.ToUInt64(Console.ReadLine());
            Console.WriteLine(n%7);

        }
    }
}

But I get WA#5. And I don't understand! Can someone help me? . . .

#include <iostream>
#include <string>
#include <stdlib.h>
using namespace std;

int main()
{
    string s;
    char ss[10];
    short l, i;
    int ostatok = 0, mnojitel = 1;
    cin >> s, ss;
    while (i < s.length() / 8)
    {
        l = s.copy(ss, 8, i*8);
        ss[9] = '\0';
        ostatok = (ostatok * 100000000 + atoi(ss)) % 7;
        i++;
    }
    for (l = 0; l < s.length() - i*8; l++)
        mnojitel *= 10;
    l = s.copy(ss, s.length() - i*8, i*8);
    ss[s.length() - i*8] = '\0';
    ostatok = (ostatok * mnojitel + atoi(ss)) % 7;
    cout << ostatok << endl;

    return 0;
}

It's work on my PC and give true results for input data from "Test Cases"

It seems timing has changed since the earlier years on the server.   When the following program gets WA in 0.015, you know 0.001 is not possible any more:

#include <stdio.h>
int main()
{
  puts( "0" );
}

Too bad that those of us solving problems now don't get time rated on the same scale as those who came before.