So, I've made programs like Prime number searchers and such. But the problem is if I use an int or long int variable for the program I am limited by the variable size. I can't search through numbers larger than their memory size. So my question is: Is there a way to allocate memory to a single variable, NOT AN ARRAY, so I can make a variable as many bytes as I want?
View 3 RepliesI'm working on a project, and can't seem to get the project to get the triangle variable to increase when the conditions are met. I need this number to be accurate so I can work out the probability.
Experiments that are either too expensive or too dangerous to perform are often simulated on a computer when the computer is able to provide a good representation of the experiment. Find out how to call the random-number generator (usually a function returning a floating point value in the range 0 to 1) for your C++ system. (Look up the functions rand and srand in the library cstdlib on the website cplusplus.com). Write a program that uses the random-number generator to simulate the dropping of glass rods that break into three pieces.
The purpose of the experiment is to estimate the probability that the lengths of the three pieces are such that they might form the sides of a triangle. For the purposes of this experiment, you may assume that the glass rod always breaks into three pieces. If you use the line segment 0 to 1 (on the real number line) as a mathematical model of the glass rod, a random-number generator (function) can be used to generate two numbers between 0 and 1 representing the coordinates of the breaks. The triangle inequality (the sum of the lengths of two sides of a triangle are always greater than the length of the third side) may be used to test the length of each piece against the lengths of the other two pieces.
To estimate the probability that the pieces of the rod form a triangle, you'll need to repeat the experiment many times and count the number of times a triangle can be formed from the pieces. The probability estimate is the number of successes divided by the total number of rods dropped. Your program should prompt the user for the number of rods to drop and allow the experiment to be repeated. Use a sentinel value of 21 to hale execution of the program.
Code:
#include <iostream>
#include <cmath>
#include <cstdlib>
#include <cfloat>
#include <iomanip>
#include <stdlib.h>
#include <time.h>
using namespace std;
float doBreak (float, float);
float doProbability (float, float);
[Code] ....
I am stuck at a problem where I have two pointers pointing to the same object, and I need to change an int on one of the pointers but point to the same object.
To be more specific, there is an array of Item objects. A long list of items a player can buy. Then, there is the player's inventory, a vector pointer. Whenever a player buys an item, it sets the pointer to the bought object.
The problem arises when he buys two of the same object. I tried to identify the objects with an ID, but it does nothing, because they are just pointing to the same object, and so I have no way of telling them apart.
This is further complicated by the fact that it is a polymorphic object. So, I can't simply make a new every time I buy an object, without making a hassle. Well, at least I am not familiar with that kind of code just yet.
I am trying to make a function that allows me to allocate memory to a "mem" variable and setting each of its chunk's status to FREE. FREE is defined as 0. Below is my code of the function.
Code:
int allocate(mem *mm, int num_chunks, int chunk_size) {
int i;
mem *temp;
if((mm = (mem *) malloc((num_chunks + 1) * chunk_size)) == NULL){
perror("Failed to Malloc
[code]...
mem; If my function works the way it should, it should print out five 0 because that is how I set them in the function, but this is not the case. I've looked at my function for 2 hours, but I could not figure out any logical error. Now, I think my problem lies with my limited knowledge of pointer arithmetic. On the other hand, when I insert 1000 as the second argument into my function, it gives seg faults, which is not the case for smaller values like 5, 10, 15, etc.
I just started deal with pointers in C, and one stuff confusing me...
Here is simple code:
int main (){
int var1 = 10;
int var2 = 20;
long ms = 10000000;
printf("Address of var1 variable: %p
", &var1 );
[Code] ...
But - when I run pmap - I don't see this addresses there:
Code:
# pmap -x 16496
16496: ./address
Address Kbytes RSS Dirty Mode Mapping
0000000000400000 4 4 0 r-x-- address
0000000000600000 4 4 4 rw--- address
00007f79cf8b8000 1576 260 0 r-x-- libc-2.12.so
00007f79cfa42000 2048 0 0 ----- libc-2.12.so
00007f79cfc42000 16 16 16 r---- libc-2.12.so
I guess - it's is inside stack:
Code:
# cat /proc/16496/maps | grep stack
7fff0d7e5000-7fff0d7fa000 rw-p 00000000 00:00 0 [stack]
But - how I can obtain this variables addreses, to see them with `pmap`? If I put them as "global":
Code: ...
#include <stdlib.h>
#include <sys/types.h>
int var1 = 10;
int var2 = 20;
int millisleep(unsigned ms);
int retpid(void);
[Code] ......
I have odd addresses in result:
Code:
Address of var1 variable: 0x600a94
Address of var2 variable: 0x600a98
How do you store a variable in memory so that it isn't changed when the program closes? I don't have any experience with this and am just wondering how it is possible. I am creating a program and want it to store your preferences and scores. In a simple program, everything is just reset and I don't want this for my program. How do I store a variable so that it stays the same, but can be changed even when the program is turned off?
View 2 Replies View Relatedrecently I developed a class header only in C++ to deal with byte arrays. Since I developed programs in other languages that had some libraries to dial with byte arrays, I developed one that the syntax is very similar to other languages.
Since I'm not very familiar with memory management, I was concerned about somethings I've read about (ex: memory fragmentation).
Here is a very simple example of my practice:
class ByteArray {
public:
ByteArray(size_t size) {
buffer = (int8_t*)malloc(size);
}
[Code].....
The class is intended to be used as part of comunication protocol in a webserver, byte arrays are created and destroyed a lot. Should I use pools? Is there a better practice? Am I doing everything wrong (laugh)?
For those who wants to see the entire class: [URL]
If I have a pointer variable indicating memory location in which we have stored what user entered and the pointer is of type volatile if the user gives the character 'a' twice , then this character will not be fetched twice from the memory but only when the character is changed???
This is the one meaning of the volatile? the other is that the value will be changed without the program itself change it?
#include <iostream>
using namespace std;
int main ()
{
[Code].....
the point of this code is to increase character by 1 (so from a to b in this case). The underlined line is the line that the system is rejecting at the moment (but there may be other issues).
I have an array that is
int arr[4][2]={{1, 3}, {5, 9}, {0,1}, {2, 0}};
and I am trying to get this code worked to find the max drop which is [1][1]
- [2,0] = 9 and min drop which is [3][0] - [3][1]=2 but my code seems to be wrong.
#include <iostream>
#include <vector>
using namespace std;
int main() {
int arr[4][2]={{1, 3}, {5, 9}, {0,1}, {8, 3}};
[Code] ....
I want to increase the value of some elements of an array according to a certain condition. For example the following code:
array <int, 100> myArray = {};
myArray.fill(0);
for(int i=1; i<5; i++)
*(myArray.being()+1) ++;
I was hoping myArray[1] = 5. But it actually did not work. But if I code:
int myVar = 0;
for(int i=1; i<5; i++)
myVar ++;
Result: myVar = 5.
I had this question for a while - is it possbile (not intended, but if this "error" can occur) to actually increase AND decrease integer with ANY operation at the same time, so the result will be screwed integer? like this
int a = 0;
//some code
a++;
//meanwhile at the very same time, not the same code, so another thread or something
a -= 5
if it would go normally, the a would == -4, however is there any way that it will screw itself, and the "a" will be -5, or 1, or just will be somehow broken?
Actually whats the size of the stack and we can increase the size?
View 1 Replies View RelatedThat code should make the size of the pointer (how many chars it can store) bigger but when i run it it show always 3 char positions while it should show N*M.
Code:
#include <stdio.h>#include <stdlib.h>
int main(void) {
int M, N, P, i;
scanf ("%d %d", &M, &N);
P = M * N;
char *c = malloc(P * sizeof(char));
[Code] ....
how we will increase the size of an arry during program execution. eg if the size of an array is 40 and during prog exexution we want to increase the size of an arry ,what is the procedure.
View 1 Replies View RelatedHow to increase font size for a specific button? I tried to change the nHeight but it doesn't seems to change the font size.
Code:
CFont font;
font.CreateFont(
12, // nHeight
0, // nWidth
0, // nEscapement
0, // nOrientation
FW_REGULAR, // nWeight
[Code] ....
Code:
#include <iostream>
using namespace std;
int main () {
char character = 'a';
[Code] .....
the point of this code is to increase character by 1 (so from a to b in this case).
The line highligted in red is the line that the system is rejecting at the moment (but there may be other issues). why it is invalid?
I'm having a problem with my homework. The task is to write a program that will take time and date typed by user, and increase it by 1 minute. I should write 3 functions - first calls second function that updates time and calls third function, if time is 00:00.Time update works, but date update does not.My whole written code:
Code:
#include<stdio.h>
struct DateAndTime {
struct date {
int day;
int month;
int year;
[code]....
I should check if inputs are numbers only, so I tried including isdigit function from ctype.h library, but that didn't work either, after I was trying it for a good hour or so, but I kinda rage quit that...
The program is supposed to have a method called Hitscore that adds a score between 0 and 1000 inputted by the user to the total score and increases level by one and print the score to the screen and which level they last completed after each entry . Have the user continue inputting scores to the program until the gamer has finished all 10 levels. After 10 levels, use a method you create called PassScore to have the program compare the score to avgscore (5000). If the score is less than avgscore, have the code respond "You are not angry at all. " if it is above avgscore, then have it respond "You seem quite angry, calm down. " and if it is exactly 5000, have it respond "Average, just average. "
//Angrybird.h
#ifndef ANGRYBIRD_H
#define ANGRYBIRD_H
using namespace std;
class Angrybird {
public:
float newscore;
float level;
[Code] .....
I'm a little lost with this program. The idea is to dynamically allocate an array and increase its size every time a new integer is inputted by the user. I believe it is a memory leak but as we have just started learning this I'm not sure how to recognise it. Sometimes I can input as many integers as I want other times 2 or 3 before it crashes. When I can input enough values i exit the loop and send it to the sort function and mean calculator function, all works fine there except the last number inputted becomes this huge value not hexadecimal though... As such I'm at a loss as what to look at next, so here you go:
#include <iostream>
using namespace std;
void SelectSort(int [], int);
float MeanCalc(int [], int);
float MedianCalc(int* [], int);
[Code] .....
I have a paradigm in a loop of queues of a vector,if a condition is true,increase sizes of the queue of that particular queue in the loop of queues, if condition is false, the queuesize is left as such in loop of queues. After this operation i need to search the queue sizes of all queues and enqueue in the shortest queue.
I want to do something like the code given below
#include <vector>
#include <queue>
int min_index = 0;
std::vector<std::queue<int> > q
std::size_t size = q.size();
[Code] ....
How to implement this logic?
will q[i].size=q[i].size+5 increase the queuesize by 5 for the ith queue?
Change the frame window size according to font size increases.
View 3 Replies View Relatedi have two loops ie.
if (n==null)
{
do loop 1
}
else //(n=!null)
{
do loop2
}
now i have to update the above code, with a single loop ie. when n==null or n!=null do the loop 1
how can i update.?
can i do like this
if(n==null ||n=!null)
{
do loop 1
}
is || operator above does the job what i expected
I have to make my program display days 1-30 along side numbers increasing by 5 each day beginning with 6 on the first day. I wrote 2 for loops on separate tabs but now I want to know if its possible to combine them into 1.
For loop 1
int day,;
for (day = 1; day <=30; day = day + 1)
For loop 2
int candy;
for (int candy = 6; candy <=151; candy = candy +5)
I'm trying to create a Makefile for a single fie ( mycod.c)
What is the syntax?
I am writing a program, the trouble is is that it uses a single thread and is SLOW.
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