I wrote this simple program to generate random genetic code comprising of ATGC. I’m pretty sure the code is correct; however, it won’t compile on my system. If someone out there could debug this it would be greatly appreciated.
This is what I have come up with.
simplest code to generate random genetic code
#include "StdAfx.h"
#include <iostream>
#include <cstdlib>
using namespace std;
(int main(
int x = rand();
if {(x % 2 == 0)
(int main(
int y = rand());
if {(y % 2 == 0)
{
cout<<"A\n";}}
else
{
cout<<"T\n";}
}))}
else
(int main(
int z = rand());
if {(z % 2 == 0)
{
cout<<"G\n";}}
else
{
cout<<"C\n";}
}))}
Related
i am getting 0xc0000005 error(access violation error), where am i wrong in this code?
i couldnt debug this error. please help me.
question is this
Formally, given a wall of infinite height, initially unpainted. There occur N operations, and in ith operation, the wall is painted upto height Hi with color Ci. Suppose in jth operation (j>i) wall is painted upto height Hj with color Cj such that Hj >= Hi, the Cith color on the wall is hidden. At the end of N operations, you have to find the number of distinct colors(>=1) visible on the wall.
#include<iostream>
#include <bits/stdc++.h>
#include <algorithm>
using namespace std;
int main()
{
int t;
cin>>t;
for(int tt= 0;tt<t;tt++)
{
int h,c;
int temp = 0;
cin>>h>>c;
int A[h], B[c];
vector<int> fc;
for(int i = 0;i<h;i++)
{
cin>>A[i];
}
for(int j =0;j<h;j++)
{
cin>>B[j];
}
if(is_sorted(A,A+h))
{
return 1;
}
if(count(A,A+h,B[0]) == h)
{
return 1;
}
for(int i = 0;i<h;i++)
{
if(A[i]>=temp)
{
temp = A[i];
}
else
{
if(temp == fc[fc.size()-1])
{
fc[fc.size()-1] = B[i];
}
else
{
fc.push_back(B[i]);
}
}
}
}
}
There are several issues.
When reading values into B, your loop check is j<h. How many elements are in B?
You later look at fc[fc.size()-1]. This is Undefined Behavior if fc is empty, and is the likely source of your problem.
Other issues:
Don't use #include <bits/stdc++.h>
Avoid using namespace std;
Variable declarations like int A[h], where h is a variable, are not standard C++. Some compilers support them as an extension.
I am trying to segment a depth image, so that values of depth between limits (low and high) remain the same, and values outside limits are set to 0.
To accomplish this I am trying to use the forEach method in OpenCV 3, to speed up the operation using all the available cores of the CPU.
Implementing the function this way, it works:
void Filter_Image(cv::Mat &img, int low, int high)
{
for (uint8_t &p : cv::Mat_<uint8_t>(img))
{
if(((p > low) && (p < high)) == false)
p = 0;
}
}
However, when I try to use the lambda expression, I only get correct results in one vertical third of the image (if you splitted the image in 3 columns, I only get the first left column well segmented). The code is as follows:
void Filter_Image(cv::Mat &img, int low, int high)
{
img.forEach<uint8_t>([&](uint8_t &p, const int * position) -> void {
if(((p > low) && (p < high)) == false)
p = 0;
});
}
The functions are called from this piece of code (simplified for testing):
#include "opencv/cv.h"
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include "config_parser.h"
#include "background_substractor.h"
#include "object_tracker.h"
#include "roi_processing.h"
#include "filtering_functions.h"
using namespace cv;
int main(int argc, char **argv)
{
Mat opencv_frame;
namedWindow("Input Video");
//parse config
VIDEO_CONFIG videoConfig;
BACK_SUBS_CONFIG backSubsConfig;
TRACKER_CONFIG trackerConfig;
ROI_CONFIG roiConfig;
FILTERING_DATA filteringData;
Parse_Config("../Config/ConfigDepthImage.json", videoConfig, backSubsConfig, trackerConfig, filteringData, roiConfig);
Display_Config(videoConfig, backSubsConfig, trackerConfig, filteringData, roiConfig);
VideoCapture videoInput(videoConfig.path.c_str());
if (!videoInput.isOpened())
{
std::cout<<"Could not open reference video"<<std::endl;
return -1;
}
while (1)
{
videoInput >> opencv_frame;
if(opencv_frame.empty())
{
std::cout<<"Empty frame"<<std::endl;
destroyWindow("Input Video");
destroyWindow("Filtered Video");
break;
}
Filter_Image(opencv_frame, filteringData.min, filteringData.max);
//show video
imshow("Input Video", opencv_frame);
waitKey((1.0/videoConfig.fps)*1000);
}
return 0;
}
The difference in results can be observed in the displayed images:
This is the good one:
And this is the bad result in the same conditions using forEach:
I cannot see the error or the difference between the two functions. The type of the image is CV_8UC1.
Could anyone provide a clue?
Thank yo all very much in advance.
I am very much new to C++11 and learning about the STL Libraries. I have written a code which is like this,
#include <bits/stdc++.h>
#include <vector>
#include <algorithm>
#include <iterator>
using namespace std;
void Print( const vector<int> &arrays )
{
for ( int x : arrays ) cout << x << ' ';
}
int main() {
int citys, cityPairs, fv, lv, w;
vector <int> fvarr;
vector <int> lvarr;
vector <int> warr;
vector <int> warr_temp;
vector <int> disjoint_pairs;
scanf("%d%d", &citys, &cityPairs);
for(int nr = 0; nr < cityPairs; nr++){
scanf("%d%d%d", &fv, &lv, &w);
fvarr.push_back(fv);
lvarr.push_back(lv);
warr.push_back(w);
warr_temp = warr;
}
for (int j = 0; j < citys; j++){
auto result = min_element(begin(warr_temp), end(warr_temp));
auto pos_temp = distance(begin(warr_temp), result);
cout << pos_temp;
auto pos = distance(begin(warr), result);
cout << pos;
disjoint_pairs.push_back(fvarr[pos]);
disjoint_pairs.push_back(lvarr[pos]);
warr_temp.erase(warr_temp.begin() + pos_temp);
}
// Print(disjoint_pairs);
}
What i am doing in this code is i am taking 3 vectors and 1 vector to copy the last one warr_temp = warr;. Then i am checking the minimum value in vectorwarr_temp and storing it's index in pos_temp, next i am storing that min value's index from vector warr into pos.
Now the problem is the first cout which is pos_temp giving me correct values but the second one which is pos giving me the output something like this,
-61-62-63-64
why is this happening? what are these numbers? are they pointers? I know that distance is a template so what is the right way to implement this?
If anyone can clear my doubts that would be very helpfull.
Sorry if stupid question!!!
The root cause of the problem is auto pos = distance(begin(warr), result); line. It gives unpredictable results because result and begin(warr) belong to different vectors.
result is iterator pointing to warr_temp element, it cannot be mixed with iterators pointing to warr elements like begin(warr).
To get element position in warr vector use std::find(begin(warr), end(warr), *result) instead:
auto warr_res = std::find(begin(warr), end(warr), *result);
auto pos = distance(begin(warr), warr_res);
I would like to interleave a random number with some alphanumeric characters, for example: HELLO mixed with the random number 25635 → H2E5L6L3O5. I know %1d controls the spacing, although I'm not sure how to interleave text between the random numbers or how accomplish this.
Code:
int main(void) {
int i;
srand(time(NULL));
for (i = 1; i <= 10; i++) {
printf("%1d", 0 + (rand() % 10));
if (i % 5 == 0) {
printf("\n");
}
}
return 0;
}
btw - if my random number generator isn't very good i'm open to suggestions - thanks
If you're okay with using C++11, you could use something like this:
#include <iostream>
#include <random>
#include <string>
int main() {
std::random_device rd;
std::default_random_engine e1(rd());
std::uniform_int_distribution<int> uniform_dist(0, 9);
std::string word = "HELLO";
for (auto ch : word) {
std::cout << ch << uniform_dist(e1);
}
std::cout << '\n';
}
...which produces e.g.:
H3E6L6L1O5
If you're stuck with an older compiler, you could use rand and srand from the standard C library for your random numbers:
#include <iostream>
#include <cstdlib>
#include <ctime>
#include <string>
int main() {
std::srand(std::time(NULL));
std::string word = "HELLO";
for (int i = 0; i < word.size(); ++i) {
std::cout << word[i] << (rand() % 10);
}
std::cout << '\n';
}
I want to use GSL's uniform random number generator. On their website, they include this sample code:
#include <stdio.h>
#include <gsl/gsl_rng.h>
int
main (void)
{
const gsl_rng_type * T;
gsl_rng * r;
int i, n = 10;
gsl_rng_env_setup();
T = gsl_rng_default;
r = gsl_rng_alloc (T);
for (i = 0; i < n; i++)
{
double u = gsl_rng_uniform (r);
printf ("%.5f\n", u);
}
gsl_rng_free (r);
return 0;
}
However, this does not rely on any seed and so, the same random numbers will be produced each time.
They also specify the following:
The generator itself can be changed using the environment variable GSL_RNG_TYPE. Here is the output of the program using a seed value of 123 and the multiple-recursive generator mrg,
$ GSL_RNG_SEED=123 GSL_RNG_TYPE=mrg ./a.out
But I don't understand how to implement this. Any ideas as to what modifications I can make to the above code to incorporate the seed?
The problem is that a new seed is not being generated. If you just want a function that returns a darn random number, and care nothing about the sticky details of how it's generated, try this. Assumes that you have the GSL installed.
#include <iostream>
#include <gsl/gsl_math.h>
#include <gsl/gsl_rng.h>
#include <sys/time.h>
float keithRandom() {
// Random number function based on the GNU Scientific Library
// Returns a random float between 0 and 1, exclusive; e.g., (0,1)
const gsl_rng_type * T;
gsl_rng * r;
gsl_rng_env_setup();
struct timeval tv; // Seed generation based on time
gettimeofday(&tv,0);
unsigned long mySeed = tv.tv_sec + tv.tv_usec;
T = gsl_rng_default; // Generator setup
r = gsl_rng_alloc (T);
gsl_rng_set(r, mySeed);
double u = gsl_rng_uniform(r); // Generate it!
gsl_rng_free (r);
return (float)u;
}
Read 18.6 Random number environment variables to see what that gsl_rng_env_setup() function is doing. It is getting a generator type and seed from environment variables.
Then see 18.3 Random number generator initialization - if you don't want to get the seed from an environment variable, you can use gsl_rng_set() to set the seed.
A complete answer to this question with a sample code can be seen in in this link.
Just for completeness I am putting a copy of the code for a function to create a seed here. It is written by Robert G. Brown: http://www.phy.duke.edu/~rgb/ .
#include <stdio.h>
#include <sys/time.h>
unsigned long int random_seed()
{
unsigned int seed;
struct timeval tv;
FILE *devrandom;
if ((devrandom = fopen("/dev/random","r")) == NULL) {
gettimeofday(&tv,0);
seed = tv.tv_sec + tv.tv_usec;
} else {
fread(&seed,sizeof(seed),1,devrandom);
fclose(devrandom);
}
return(seed);
}
But from my own experience with this function, I would say that the dev/random solution is very time consuming compared to the gettimeofday(), you can check it out. So, the gettimeofday() solution, might be better for you if its level of accuracy is enough:
#include <stdio.h>
#include <sys/time.h>
unsigned long int random_seed()
{
struct timeval tv;
gettimeofday(&tv,0);
return (tv.tv_sec + tv.tv_usec);
}