i use dev c++...i write this code to reverse an array and save the result in the same one
if n=3 i expect
a[0]=0 a[1]=1 a[2]=2 (before rev is OK but after calling rev)
a[0]=2 a[1]=1 a[2]=0 (expected result )
but i get
n=3
[code].....
node = pool.at(0) is executed even though pool is empty,
I even tried pool.size() == 0, that line is still executed. What is the reason, I wonder?
Code:
NodePoolNode* NodePool::acquireNode(int x, int y, long t) {
std::stringstream key;
key << x << ":" << y << ":" << t;
NodePoolNode* node = usedNodes[key.str().c_str()];
if (node == NULL) {
[Code] ....
I found this piece code on the following site:
[URL]
I predicted the outcome as being 01230 as I thought the prefix decrement operator on iterator ce would prevent the final element of the list from being transformed.
I was wrong, the correct output is 01234.
So, I removed the decrement prefix and ran the test again, expecting a different result. It wasn't! The result was still 01234.
Only when I decremented ce twice did I get the result I initially expected, 01230.
why the first decrement of ce appears to have no effect?
#include <algorithm>
#include <functional>
#include <iostream>
#include <iterator>
#include <list>
#include <cstdio>
int main() {
typedef std::list<int> L;
[code]....
The program should store a character array in reverse order then display the reversed array. I have also included in the code that will display the actual characters into the array as it loops through. So I know the characters are being stored, but why doesn't it display the entire string when I call it?
Code:
#include<stdio.h>
int main(){
char str[50];
char rev[50];
printf("Enter Desired Text: ");
scanf ("%[^
[Code] ....
Is it just my compiler?
I am trying to compare 2 strings of characters The users input containing 5 chars is compared to a table If the input is already be existent in the table the index of those chars in the table is printed Quest: how to copy the result of a printf() into an array ? The last printf() gives a sequence of numbers and I am trying to save that sequence to another array for further operation ! I have not been able to do that so far even with tmp[]=i ;
Code:
#include <stdio.h>
#include <string.h>
#define N 30
#define n 100
int main (void)
[code]....
I do not have code - I am just wondering if I have a method which gets input from the keyboard and returns it, how would I store that information in a new method after calling it and put the result of it into an array.
View 3 Replies View RelatedI am trying to write a program that reverses the elements of an array by using an function 'myreverse'. The function should reverse original array and return nothing.
In my program, the function 'myreverse' is not getting invoked and the original array is being displayed as it is.
#include <iostream>
using namespace std;
void myreverse(int arr[],int n) {
int *p=&arr[n-1];
int temp;
for(int i=0;i<n;++i)
[Code] .....
I have been trying this for so long. I need to make a separate function named reverseDiagonal where I have to reverse the diagonals in a 2D array.. I have tried swapping it but i don't know where to place the "cout" and print the diagonal.
View 4 Replies View RelatedI am trying to print the array of string using this code but the compiler is printing null in the output:
The code is as follows:
char *arr[10];
int i;
for(i=0;i<10;i++)
scanf("%s",*(arr+i));
for(i=0;i<10;i++)
printf("%s
",*(arr+i));
Code:
#include <stdio.h>
#include <string.h>
#include <conio.h>
#include <math.h>
void reverseAr(char ar[], int n);
int main() {
int choice;
char *abc= ar[];
[Code]...
My codes keep couldn't get the reverse array of characters.
Is it possible to prompt information from user then display the result in a one dimensional array form? If yes, how should i link them together?
View 7 Replies View RelatedEg. User input : abcde
Program Output : edcba
I keep on getting weird ASCI symbol in return, I couldn't achieve what I need, and tried debugging for days,
Code: char ar[20];
int len,n=0;
printf("enter the string to be reversed :
");
[Code].....
Here's my program: - Program which inputs a string from user, reverses it and displays it.
#include <iostream>
using namespace std;
void string_reverse (char [], const int);
int main() {
const int arraysize = 10;
char string[arraysize];
[Code] ....
In the string_reverse function, I have declared temp character type array but on line 38, the
compiler is throwing 3 errors: -
error C2057: expected constant expression
error C2466: cannot allocate an array of constant size 0
error C2133: 'temp' : unknown size
I have declared a constant integer arraysize in line 35. Now I have no clue why is this happening because I think as I have declared it as a constant integer variable, this should not happen.
I had the following question in my exam paper and only got 1.5 out of a possible 6 marks. This is the question:
Given the Matrix class:
class Matrix {
public:
Matrix(unsigned r, unsigned c);
Matrix(const Matrix<T>& rhs);
~Matrix();
const Matrix<T>&operator=(const Matrix<T>& rhs);
[Code] ....
Use the linkedStackType class (Array implementation of stack) and write a function reverseCols to reverse the order of columns in the matrix. Note that reverseCols is not a member function of the Matrix class therefore only the public interface of matrix can be used.
//Implementation of Stacks as Array
template<class Type>
class stackType: public stackADT<Type> {
public:
const stackType<Type>& operator=(const stackType<Type>&);
[Code] ....
What is the correct solution must be to reverse the columns of the matrix?
I need fastest method to reverse order of bytes in my char array.
For example i have:
unsigned char buf[8];
// consider data stored in buf is 88 77 66 55 44 33 22 11
// how to reverse it to: 11 22 33 44 55 66 77 88
// currently i can do it by equal assignment , i make another buf like:
unsigned char buf_ok[8];
[Code] ....
// This does reverse the bytes as i want but its very slow , i am looking for fast method ..
I'm trying to use a priority queue sorting in reverse order to take a vector or 2d array. The problem is that I want to sort by the vector/array cell value but keep the reference to the vector/array index of the value. I don't know quite howto keep them both related so when I pop. I can find the corresponding cell.
priority_queue<int, vector<int>, greater<int> > Open;
Using the array to accept 10 testscore. Calculate and print the highest, lowest, fifth test score entered and all the test score entered in reverse order.
How i would get it to print the highest,and lowest and in reverse order. I'm confused as to what to do...
I am currently trying to understand why this example for using an array as an argument in a function has a different result than what the lecture notes say it should be.
So supposedly sum should return with the value 28, but I get 27 no matter what. I also am not very good at reading and understanding what exactly the order of operations for this function are.
Code:
#include <iostream>
using namespace std;
int sum(const int array[], const int length) {
long sum = 0;
for (int i = 0; i < length; sum += array[++i]);
return sum;
[Code] ....
I tried running the code below and i got an unexpected output
Code:
#include<stdio.h>
void main() {
char a='A';
while(a)
[Code] ....
The code is supossed to give an infinite loop but instead it terminates with a=0...I tried running it with some casting like this
Code:
#include<stdio.h>
void main(){
char a='A';
while((int)a)
[Code] ....
But the output was the same as before.why the code has this unexpected behaviour???
I am working through Binary IO with objects and am running into a curious error.
The program executes perfectly until it hits the very end. At "return 0", the program fails. The debugger picks up SIGABRT when executing "return 0". This seems to me to indicate a deconstructor problem of some kind. However, I can't seem to find any deconstructor problems (I am fairly new at programming though).
If I comment out the following two lines:
"binaryio.read(reinterpret_cast<char *>(&studentNew1), sizeof(Student));"
"binaryio.read(reinterpret_cast<char *>(&studentNew2), sizeof(Student));"
then the program finishes exiting without error . . . . but the whole point is to be able to read from the binary file. With those two lines in the code, the program successfully reads from the file and outputs the objects to the console ,but fails at "return 0";
Here is the code:
#include <iostream>
#include <fstream>
#include "Student.h"
using namespace std;
void displayStudent(Student student) {
cout << student.getFirstName() << " ";
[Code] .....
I have the following piece of code which should write the contents of my vetor to y file but I am getting a very weird output in my file.
for (int i=0;i<amount;i++) {
fprintf(pFileO,"Case #%d: ",i+1);
for (int j=0;j<words[i].size();j++) {
[Code].....
As you can see this doesn't make sene because the file should also contain the exact same things as the cmd outputs. What's going on here ?
I'm getting unexpected output in 2 different cases. The 1st deals with bitfields. The C++ standard has this line about integral promotions:
An rvalue for an integral bit-field (9.6) can be converted to an rvalue of type int if int can represent all the values of the
bit-field; otherwise, it can be converted to unsigned int if unsigned int can represent all the values of the bit-field.
If the bit-field is larger yet, no integral promotion applies to it. If the bit-field has an enumerated type, it is treated as any other value of that type for promotion purposes.
This sounds like the value of a bitfield will always be treated as a signed int if the signed representation of the value will fit in the bits. This seems to hold true for my C compiler, but not my C++ compiler.
I tried storing a small negative value in a bitfield that has enough bits to store the sign bit and the value. But when I print out the bitfield, I always get a large number
In the example code below, I expect the output:
Code:
foo.x = -1
foo.y = -2
foo2.x = 31
foo2.y = 6
foo3.x = -1
foo4.x = 4294967295 But I get: Code: foo.x = 31
foo.y = 6
foo2.x = 31
foo2.y = 6
foo3.x = -1
foo4.x = -1 -------------------
The other issue I'm having is sort of similar. I'm trying to store 4294967295 into a float, but when I print it out, I get 4294967296. i've tried storing a few other large values like this and what's printed out is rarely the value I stored. I thought it might be because of some int to float conversion, so I tried 4294967295.0. Still no luck. Then I remember that defaults to a double so maybe that's the issue so I tried 4294967295.0f. Still no luck. Why can't I store the correct value here? I don't think it's an IEE format thing since I can use these values as floats on a calculator program.
The example code showing both issues is below.
Code:
#include <stdio.h>
typedef struct {
signed char x : 5;
signed char y : 3;
}my_struct_t;
[Code] .....
My compiler (GCC) keeps expecting an expression where it shouldn't in 1 specific piece of my code:
int zxcNewWindow( HWND parent, TCHAR *text, zxWINDOW *kid,
UINT style, int x, int y, int w, int h, int type )
// right here
{
*kid = zxDefWINDOW;
The project contains only 2 files right now and the settings are just the default for an empty Code::Blocks 12.11 project. Both files are in UTF-8 format (tried in ASCII too), I just cannot see why this is not compiling correctly. I'll post the files in the next two posts.
Edit: For those of you who didn't get what the error was from the above here's the full log:
mingw32-gcc.exe -Wall -g -DzxDEBUG -c C:MePrjscppzxGUImain.c -o objmain.o
C:MePrjscppzxGUImain.c: In function 'zxcNewWindow':
C:MePrjscppzxGUImain.c:39:10: error: expected expression before '{' token
Process terminated with status 1 (0 minutes, 0 seconds)
1 errors, 0 warnings (0 minutes, 0 seconds)
I'm just starting c++, doing tutorials. So many tutorials. I've noticed that the tutorials all assume the same thing: That the user will always do exactly as he/she is told when asked for input.
Example: "Please enter your age:"
Now, the example code might be expecting the user to type some numbers, but what if the user feels like typing out the letters of their age?
"I am ninety five thank you very much, sonny"
I could specify to the user that I only want the information in number form, but what if the user is just being a dick?
What if the user types, "none o' yer business."?
So... how to approach "fool-proofing" player input?
I have written this regex to match a floating point literal:
(^[[:space:]]*)(([0-9]+.?[0-9]*([eE][+-]?[0-9]+)?)|"
"(.[0-9]+([eE][+-]?[0-9]+)?))([fFdD]?[[:space:]]*)$
and when I match it with string like "123e" or "e2" it works while it shouldn't and I can't find the reason why.
I keep getting a segmentation error when ever I have the following code...
int main(void) {
//Section 1
unsigned long val = 12;
std::vector<unsigned long> vval;
for(unsigned long i = 0; i < 100; ++i) {
vval.push_back((unsigned long)0);
[Code] ....
Error: *** Error in `/home/alex/projects/bignum/build/bignum': free(): invalid pointer: 0x00007ffff75b5b88 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x80a46)[0x7ffff7274a46]
compiler is clang++ 3.2
It doesn't happen if I restructure it so that bignum::num is not a pointer to an std::vector<unsigned long>