im the biggest noob ever and i need mad help (shuld be easY)

[C++noob]

well guys i need u to write this easy program for me because i am a complete retard stuck in class without a clue... this is what i get ::

the height of an object dropped from a starting point of 100 meters is given by the equation h=100-4.98*t*t .. where t is the time in seconds. write a program that ask the user for a time less then 20 seconds and displays the height of the object at that time using this formula. the program output should look similar to

enter the time :
the object is at :


thankyou so much u have no idea.. and if ur relli good at this stuff i get 5 project to do a day .. ill keep them comin

[twm]

You're asking us to do your work for you and cross-posting it? Geez...

[RecursiveS]

You may get someone to write your code for you - but it will probably cost you quite a few dollars - best of luck.

[RecursiveS]

Oh, and pleasedon't double post - it's very annoying.

[jgbauman]

Since you asked so nice and showed so much effort, here is an solution ;-)

Code: Select all

(begin
(display "enter the time : ")
(let
  ((t (read)))
  (display "the object is at : ")
  (display (- 100 (* 4.98 t t)))
  (display "\n")))

[Alvaro]

jgbauman's solution is nice. All you have to do now is write a Lisp interpreter in C++ and hand it over to your teacher.

[Alvaro]

This program is not very portable. But I still like it.

Code: Select all

#include <iostream>
#include <map>
#include <queue>
#include <stack>
#include <string>

using namespace std;

enum {EXIT,PRINTS,PRINT,INPUT,PUSH,PUSHV,MULTIPLY,DIVIDE,SUBSTRACT,POPV};

int p[]={
   PRINTS,(int)"enter the time: ",
   INPUT,(int)"t",
   PUSH,100,
   PUSH,498,
   PUSH,100,
   DIVIDE, 
   PUSHV,(int)"t",
   PUSHV,(int)"t",
   MULTIPLY,
   MULTIPLY,
   SUBSTRACT,
   POPV,(int)"v",
   PRINTS,(int)"the object is at: ",
   PRINT,(int)"v",
   PRINTS,(int)"\n",
   EXIT
};

int main(void){
   map<string,double> v;
   stack<double> s;
   int i=0;
           
   while(1){
      switch(p[i++]){
      case EXIT:
         return 0;
      case PRINTS:
         cout << (char *)p[i++];break;
      case PRINT:
         cout << v[(char *)p[i++]];break;
      case INPUT:
         cin >> v[(char *)p[i++]];break;
      case PUSH:
         s.push((double)p[i++]);break;
      case PUSHV:
         s.push(v[(char *)p[i++]]);break;
      case MULTIPLY:
         {double t=s.top();s.pop();s.top()*=t;}break;
      case DIVIDE:
         {double t=s.top();s.pop();s.top()/=t;}break;
      case SUBSTRACT:
         {double t=s.top();s.pop();s.top()-=t;}break;
      case POPV:
         v[(char *)p[i++]]=s.top();s.pop();break;
      }
   }   
}



[Jimbo]

hm... Alvaro's code is cheaper than mine, but your teacher will have to be completely senile to not notice anything about it...

starting price for something like this is $50 btw... (and if you are willing to pay, you'll have almost immediate results)

[Justin]

nice alvaro. here's something a bit more portable

Code: Select all

<?php

function show_form() {
  echo "<form action=\"\" method=\"post\">\r\n  Enter the time:&nbsp;&nbsp;&nbsp;<input type=\"text\" name=\"time\" size=\"40\"><br><input type=\"submit\" value=\"Go\">\r\n</form>";
}

if ( !isset($_POST['time']))
  die(show_form());

$t = $_POST['time'];

if ( !ctype_digit($t)) {
  echo "Data must be numeric\n";
  die(show_form());
}

if ($t > 20 || $t < 1) {
  echo "Enter a time between 1 and 20\n";
  die(show_form());
}

$h = 100-4.98*$t*$t;

echo "The object is at: $h";
?>

I like how he throws us a bone at the end.

and if ur relli good at this stuff i get 5 project to do a day .. ill keep them comin

[Jimbo]

just an afterthought but... either my mental math sucks, or the object hits the ground at ~sqrt(20) sec...

or does it fall into a nice little hole?

[foolguitardude]

Code: Select all

#include <iostream.h>

int main()
{
   double seconds = 0;
   double total = 0;
   cout<<"Please enter a number lower than 20: ";
   cin>>seconds;
   cout<<"\n";

   if(seconds < 20)
   {      
      total = (100-(4.98*seconds))*seconds;
      cout<<"The object is at: ";
      cout<<total;
      cout<<"\n\n";
   }
   else
   {
      cout<<"Invalid input\n\n";
   }
   return 0;
}


This is the last one you get for free.

[MXP]

For free? That code is incorrect anyway. There is no iostream.h in C++

[jgbauman]

just an afterthought but... either my mental math sucks, or the object hits the ground at ~sqrt(20) sec...

or does it fall into a nice little hole?

Newest scientific studies showed that in contrast to the now general believe, earth is indeed flat. And if you drop an object 100 meters above the edge. It simply falls of the earth and so can have negative heights. Simple, eh?

And if you don't believe me, noob's formula proofs it.
And since it can be implemented on a computer and computers are always right (and operated by people in white lab coats, as shown in most movies about early computers) it must be true.

[omnius]

Code: Select all

#include <iostream.h>

int main()
{
   double seconds = 0;
   double total = 0;
   cout<<"Please enter a number lower than 20: ";
   cin>>seconds;
   cout<<"\n";

   if(seconds < 20)
   {      
      total = (100-(4.98*seconds))*seconds;
      cout<<"The object is at: ";
      cout<<total;
      cout<<"\n\n";
   }
   else
   {
      cout<<"Invalid input\n\n";
   }
   return 0;
}


This is the last one you get for free.

Minor point on style. You declare total at the start of main but don't use it until further down your code. Not only that, but if an invalid number of seconds is entered you don't use total at all. Consider declaring total in the smallest scope necessary, which in this case is inside the block of the if statement. If you declare it thus:

Code: Select all

   if(seconds < 20)
   {      
      double total = (100-(4.98*seconds))*seconds;
      cout<<"The object is at: ";
      cout<<total;
      cout<<"\n\n";
   }


then you reduce the scope of total to just where it's used, and initialise it with a value at the point of declaration rather than initialising it with zero before you need it.

It's not such a big deal in a small simple program of the type posted here, but these are good habits to form.

[Justin]

very well put