DDR's questions

I am doing a basic program that does calculations with very large numbers, what I do is read it as Stringand the idea is that I multiply each digit of the number by a large number (for example 100000).

#include <stdio.h>
#include <string.h>
#include <math.h>



int main( ) {
  char cadena[1000];
  char cadena2[1000];

  scanf( "%s", cadena2 );

  for( unsigned i = 0; i < strlen( cadena2 ); ++i ) {
    cadena[i] = cadena2[i] - '0';
    cadena[i] *= 100000;
    cadena[i] = cadena[i] + '0';
  }

  printf( "%s", cadena);

  return 0;
}

but logically it overflows and at the time of printing, that is, what is expected does not come out.

My question is how can I save a number so large that it should only be read as String?

Thank you!

PS: I had already asked a question associated with this topic . Operation with a numeric value of a digit does not produce the expected result.

I have this little code

void main()
{
    int len,i;
    int rta[64];
    char numero[64];
    scanf("%s",numero);
    len = strlen(numero);
    i=0;
    for (i=0; i<len; i++){
        rta[i]=(int)numero[i]*2;
    }
    printf(rta);
}

Whose input is 113and result should be 226, but instead it gives me the following resultb

The idea is to convert the numbers to int 's and then operate on them since I need it to read it as a string initially.

Any ideas?

Thank you!

For example I have this variablevar

int var=200;

How can I know what type is a variable ( int, String, boolean...)?

Since if I print it I don't know if it's a intor a String(in this case).

I am doing a trigger in sql which concatenates a word with a number, like this:

create or replace trigger TG_curso_Auto
before insert on cursos
for each row
declare  var int;
begin
    select count(*)+1  into var from cursos;
    :new.siglas := concat(:new.siglas,'-',var);
end;
/

Here var is an integer type variable that I need to concatenate with a string, but I don't know how to pass it to a string, the courses table simply has an id and an acronym

create table cursos
     id number(7) not null,
     siglas varchar(4) not null);

To better explain the var starts from 1 and as something is added to it, it adds 1 by 1... when trying to insert in the table courses for example ( insert into cursos values (12345,'Bases')) you should put in the column acronyms Bases-1 then something like acronyms-2 , initials-3 ...

Any ideas how to solve this problem or is it not possible to do this?

Thank you!

I am making a program with functions and a global variable, the idea was to handle a global variable in several functions, I don't know how to make global functions, this is what I tried:

#include<cmath>
#include <stdio.h>
#include <iostream>

using namespace std;

int number=3;

void main(){
    cout<<number;
}

void main(){but I have no idea of ​​the syntax mark on it because if it is supposed to numberbe a global variable.

What is the problem?

I am trying to make a loop that reads a string as long as it is not empty, if it does not contain any character then the loop is exited; but I have not been able to get it, it stays in a loop and never exits, here is my code:

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

int main(){
    string nombre;
    cout<<"ingrese una palabra "; cin>>nombre;
    while (nombre[0] !='\0'){
        cout<<nombre<<endl;
        cout<<"ingrese una palabra "; cin>>nombre;
    }
}

My problem is in the while condition (nombre[0] !='\0')that apparently doesn't read it for some reason.

Why does it not meet this condition?

Thanks.

i am new to c++ language and i have a problem with this loop.

#include<iostream>
using namespace std;

int main(){
    int iterador=0;
    while (iterador<=10){
        cout<<iterador<<endl;
        iterador+=1;

    cout<<"si";

    }
}

It is supposed to print the numbers from 0 to 10 and then print something (I put "yes" to mislead) but when I run it, it prints it as follows:

0
si1
si2
si3
si4
si5
si6
si7
si8
si9
si1
si

and what I wanted was this!

0
1
2
3
4
5
6
7
8
9
1
si

Can someone explain to me why C++ does this, why it does this or how C++ works with loops?

Thank you!

I have a list (containing only the numbers 0 or 1) with a quantity X of 0, for example 4:

[0,0,0,0]

And I need to find all possible combinations with these numbers, that is:

[1,0,0,0], [0,1,0,0], [0,0,1,0], [1,1,0,0] ........ [1,1,1,1]

But that's a lot of combinations, so I'm not sure which method to use.

I have consulted a method called Bitmask which can solve the problem, I tried to do it with a nested for but it was not possible.

Is there a practical way or algorithm for this problem?

I have seen in some programs and on the web that they use the assert function , for example:

Assert True

Does nothing, while:

Assert False 

Send an AssertationError...

It is still not clear to me what this function is for.

Any ideas ?

Thank you!

I have been studying the topic of graphs in python, and I came across Topological-Sort which is a graph ordering method; but I still don't fully understand how to perform this method in python, I know the theory of this ordering and how it should work but I don't know how to apply it to python, for example:

We have a degree of 6 nodes, whose unions are the following: (5,2),(5,0),(4,0),(4,1),(2,3),(3,1).

With this we can know the 'Weight' of each node that would be:

weight of 5 -> 0
weight of 4 -> 0
weight of 3 -> 1
weight of 2 -> 1
weight of > 1 -> 1
weight of 0 -> 2

then the order from smallest to largest would be: 5 4 2 3 1 0

My doubt is how the python codes that do this sorting work, since I want to implement one but I'm not sure how to do it. Here is some code that I found:

#Python program to print topological sorting of a DAG
from collections import defaultdict

#Class to represent a graph
class Graph:
    def __init__(self,vertices):
        self.graph = defaultdict(list) #dictionary containing adjacency List
        self.V = vertices #No. of vertices

    # function to add an edge to graph
    def addEdge(self,u,v):
        self.graph[u].append(v)

    # A recursive function used by topologicalSort
    def topologicalSortUtil(self,v,visited,stack):

        # Mark the current node as visited.
        visited[v] = True

        # Recur for all the vertices adjacent to this vertex
        for i in self.graph[v]:
            if visited[i] == False:
                self.topologicalSortUtil(i,visited,stack)

        # Push current vertex to stack which stores result
        stack.insert(0,v)

    # The function to do Topological Sort. It uses recursive 
    # topologicalSortUtil()
    def topologicalSort(self):
        # Mark all the vertices as not visited
        visited = [False]*self.V
        stack =[]

        # Call the recursive helper function to store Topological
        # Sort starting from all vertices one by one
        for i in range(self.V):
            if visited[i] == False:
                self.topologicalSortUtil(i,visited,stack)

        # Print contents of stack
        print stack

reference: topological-sort-code

I'm just asking for a little guide on how this code works so I can implement my own code

I have the following list:

[0, 1, 2, 3, 4, 6, 6, 17, 16, 9, 10, 23, 12, 13, 14, 15, 16, 17, 18, 4, 20, 4, 22, 23, 24, 4, 4]

I wanted to know how to find the number with the most repetitions without using a cycle since I don't see this as very practical, especially with very long lists. My idea was to use a dictionary whose elements have those of the list and here if you check the number with more repetitions through a for, however it is a process that can be very long but can be effective; and the last idea was to use the function countin a loop that checks each element of the list set.

Is there a more efficient way to solve this problem? Any ideas?

Thank you!

I have a question with Stdin.readlines, I'm not sure how to use it; for example I have this paragraph

Adventures in Disneyland Two blondes were going to Disneyland when they came to a fork in the road. The sign reads: "Disneyland Left." So they went home.

But when I print it I get something like this:

['Adventures in DisneylandTwo blondes were going to Disneyland when they came to  fork in the road. The sign read: "Disneyland Left." So they went home.\n', '\n']

My idea was that each word would be separated as an element, but here an element is a phrase, My input is Mensaje=stdin.readlines(), but I don't know how to use this very well, I've tried to put a split()or strip()but this gives me an attribute error.

Can someone explain to me how it works stdin.readlines()and what attributes it has?

Thank you!

I have a list with 2 elements a=[1,2]if I put for example a[2] then it will mark

> > Traceback (most recent call last):   File "<pyshell#13>", line 1, in <module>
>     if a[2]== IndexError(): IndexError: list index out of range

If I put a ifto 'fix it' that says for example:

 if a[2]== IndexError: 
       print('Fuera de Rango')

Logical It won't work.

I know there are several ways to solve this problem such as:

if a[2]==len(a):
    print('Fuera de Rango')

But the main question is whether the error can be avoided directly as in the first example without the need to put a condition like the length or something like that, but using a function that avoids these errors.

Thank you! and I hope I made myself understood.

Let's suppose that I have this string a='12345&&&4554444', how do I read only the numbers of said string without the need to do it with a loop since the only way I know is by looping through the list.

variable=str('')
for i in a:
    if i!='&':
         variable+=i
print(variable)

whose output would be:

   1234545564444

Is there another way to do this??

Thank you!

I use this the following input to enter a list of numbers, for example this list: 1 2 3 4 5 6

a=stdin.readline().strip().split()

if I give print(a)it the show me ['1','2','3','4','5','6'], my question is if that input can be modified in such a way that it shows me the list of integers ( [1,2,3,4,5,6]) but not of strings, or is it simply not possible?

I have this list A:

A = ['-1', '-2', '-2', '1', '1', '10', '100', '20', '4']

if i put sorted(A)this i get

['1', '1', '-1', '20', '4', '-2', '-2', '10', '100']

I tried this list:

lista = ['3', '2', '5', '6', '7']

and if I repeat this process, that is sorted(lista), it prints it sorted but, for some reason, I have problems with negative numbers. I don't understand why Python doesn't order it properly anymore.

What I needed was for me to organize a list of string numbers, without the need to return them to integers and without using any loops .

Any idea why this is happening and if it can be fixed?

I need to read several lines in python 3, I have this without pressing ENTER: Love Roma Hello Hello occasionally Staggering bear dog Posesionarais posesionarias Colombia Locombia Mama Mami and I need python to read all the lines and print me in a list [[Amor,roma]. [Hello Hello]......]

Any way to solve this? Thank you!