Consider this piece of code from the following website: [URL] .....
Code: unsigned intx = 50; x += (x << 2) + 1;
The website above says the following about the code:
Although this is a valid manipulation, the result of the shift depends on the underlying representation of the integer type and is consequently implementation-defined.
How exactly would a legal left shift operation on an unsigned integer result in implementation-defined behaviour?
I have a double variable and depending on certain conditions I need to set certain bits of an unsigned short Variable. For example, if double var is odd I need to set the 15th bit of the unsigned short variable.
I am having problems copying outputs of the above code into other unsigned char other[32]. I need to keep the output of dev/urandom for backup. But, when I try to assign the values by memcpy(other, key, 32), the values do not match. The same problem happens by assigning values index by index in a loop.
I am making a program that formats a string. I want to create a new 2 dimensional string that will have many other chars and strings in it beside the original string. Then I split the string up on the newlines and return it. Adding different parts to the 2d string e.g. I need to add five _ as chars not string then I need to add different things. First I use sprintf () to add as much as possible. And then I do what to add the rest?
I am having some trouble performing this. I am not sure, if my unsigned char arrays are null terminated, but I don't think so. Here is my code: They are supposed to be byte arrays of size 16.
int setkey(unsigned char* ky) { printf("INSIDE POLY-DEL ... key byte array passed in HEX: "); int i; for (i = 0; i < (int)16; i++)
How do you use char instead of unsigned to calculate numbers? This is using char only and nothing else.
Step 1: I ask the user to enter a number. Step 2: User enters a number. Step 3: Number user entered is going to be that number squared or cubed or w/e.
For example; "Enter a number: " 3 " Number you entered multiplied four times: " 81 (Since (3)*(3)*(3)*(3) = 81)
Another example; "Enter a number: " 5 " Number you entered multiplied four times: " 625 (Since (5)*(5)*(5)*(5) = 625)
Code: Char num; cout << "Enter a number"; cin >> num; cout << "Number you entered multiplied four times: " << (num)*(num)*(num)*(num) << endl;
I came across some code and it's not clear why it is casting an unsigned char * to another pointer type only to free it right after. Here are the relevant structures:
As you can see, _Edge_Message has a *msg field, but in the function below, they cast it to the other two structure types inside the case blocks of the switch statement only to free it. What is the point or advantage of doing this?
Code: void _edje_message_free(Edje_Message *em) { if (em->msg) { int i; switch (em->type) {
The characters show up in the list box as short unreadable characters. like it is chopped.
If i change to : Sendmessage(hndl, listboxupdate,0 , (LPARAM)&buf[15]);
Then I can see readable valid strings of up to 50 characters and then empty unreadable characters afterwards. I tried all kinds of things , including using CString, still did not work.
I have an embedded microcontroller system communicating with a similar system by radio. The api for the radio requires data to be transmitted as an unsigned char array. It will always transmit a positive integer in the range 0 to 255.When I receive the data I am having difficult in extracting this positive integer.
Code: unsigned char rxData[4]={'1','2','3',''}; int inVal=0;
//want to assign inVal whatever number was transmitted
E.g. 123
I've been at this for a week and have tried at least 10 different approaches including the use of the atoi(), copying the absolute value of each element of rxData into another char array, reinterpret_cast, and others.
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 ..
Where col is a 'vec4' struct with a double[4] with values between 0 and 1 (this is checked and clamped elsewhere, and the output is safely within bounds). This is basically used to store rgb and intensity values.
Now, when I add a constant integer as a pixel value, i.e.:
buffer_rgb[i] = ((unsigned char)255;
Everything works as it should. However, when I use the above code, where col is different for every sample sent to the buffer, the resulting image becomes skewed in a weird way, as if the buffer writing is becoming offset as it goes.
You can see in the 'noskew' image all pixels are the same value, from just using an unchanging int to set them. It seems to work with any value between 0-255 but fails only when this value is pulled from my changing col array.
Whole function is here:
// adds sample to pixel. coordinates must be between (-1,1) void Frame::addSample(vec4 col, double contrib, double x, double y) { if (x < -1 || x >= 1 || y < -_aaspect || y >= _aaspect) {
Now i want to convert this into a unsigned char pointer.
unsigned char * pBMPHeaderData;
I already got the raw image data in another unsigned char buffer.
unsigned char* pRawBMPData;
Now i want to make a complete BMP image by adding the header info and raw data into a new unsigned char pointer. For this i need to convert the BITMAPINFO struct into a unsigned char *
I have a problem I am working on where I need to sort some data based on the values of a string of bits. The strings look like this,
010000001110000000
there are 18 bits, 1 means a feature is present, 0 means the feature is absent.
Each of these string has 4 on bits. I need to sort them such that I have the longest possible runs with 3 of the same on bits. It doesn't matter which 3 bits are on, I am just looking to order them in blocks with the longest possible runs. As a second step, the ordered blocks will be sorted by size large>small.
The following data is ordered like I need it to be.
Code: // block 1, run of 12, keys 1,2,11 are identical (key 12 is also identical) 011000000001100000 011000000001100000 011000000001100000 011000000001100000
[Code] .....
This is the sort order that I am looking for. I need to be able to take a list of the bit strings in any particular order and sort them into the order above. The algorithm would need to recognize that there are 4 on keys and then look for groupings of three common on keys.
This is more of an algorithm question than one about specific implementation in code. I generally assume that most programming problems have been solved one way or another, so I don't know much about analyzing and manipulating strings of bits.
Is there a standard method for this kind of pattern recognition?
How can i write a function that will read an "unsigned integer" into a variable of type "unsigned short int"? i can not use cin >> inside the function.. so i am looking for atleast a hint!
I am trying to assign the integer value to unsigned char array. But it is not storing the integer values. It prints the ascii values. Here the code snippet
The values which are stored in uc[] is ascii values.I need the integer values to be stored in uc[]. I tried to do it with sprintf. but the output is not as expected. if I print the uc[i] it should diplay the value as 0,1,2....99.
I am working on a project where I need to retrive a double number and store 8 bits of the number in one field and the other 16 bits in another field. the code below gives me an error.
lata= lat>>8; latb = (lat & 0xff);
The error states that & and >> are illegal for double. With this in mind, can I use these on a double. If not what can I do to achieve what I am trying to do?
I have the codes for such a problem where, to create a program that counts how many times the second string appears on the first string. Yes it counts if you put 1 letter only, but if you put 2, it is an error. As an example. If the first string is Harry Partear, and the second string is ar, it must count as 3. Here's the code:
Code:
#include <iostream> #include <conio.h> using namespace std; int main ()