I am doing Week 4 Filter-less for CS50, I get an error whne I try to compile my code
When I complie it is see this erorr.
/usr/bin/ld: /lib/x86_64-linux-gnu/Scrt1.o: in function _start': (.text+0x1b): undefined reference to main'
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [: helpers] Error 1
This is my code
#include "helpers.h"
#include <math.h>
// Convert image to grayscale
void grayscale(int height, int width, RGBTRIPLE image[height][width])
{
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
float r = image[i][j].rgbtRed;
float g = image[i][j].rgbtGreen;
float b = image[i][j].rgbtBlue;
float grey = round((b + g + r)/3.0);
image[i][j].rgbtRed = image[i][j].rgbtGreen = image[i][j].rgbtBlue = grey;
}
}
return;
}
// Convert image to sepia
void sepia(int height, int width, RGBTRIPLE image[height][width])
{
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width / 2; j++)
{
int w = width - (j + 1);
RGBTRIPLE tmp = image[i][j];
image[i][j] = image[i][w];
image[i][w] = tmp;
}
}
return;
}
// Reflect image horizontally
void reflect(int height, int width, RGBTRIPLE image[height][width])
{
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
int b = image[i][j].rgbtBlue;
int g = image[i][j].rgbtGreen;
int r = image[i][j].rgbtRed;
int sepiaRed = round((0.393 * r) + (0.769 * g) + (0.189 * b));
int sepiaGreen = round((0.349 * r) + (0.686 * g) + (0.168 * b));
int sepiaBlue = round((0.272 * r) + (0.534 * g) + (0.131 * b));
if (sepiaRed > 255)
{
sepiaRed = 255;
}
if (sepiaGreen > 255)
{
sepiaGreen = 255;
}
if (sepiaBlue > 255)
{
sepiaBlue = 255;
}
image[i][j].rgbtBlue = sepiaBlue;
image[i][j].rgbtGreen = sepiaGreen;
image[i][j].rgbtRed = sepiaRed;
}
}
return;
}
// Blur image
void blur(int height, int width, RGBTRIPLE image[height][width])
{
RGBTRIPLE tmp[height][width];
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
tmp[i][j] = image[i][j];
}
}
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
int totalRed = 0;
int totalGreen = 0;
int totalBlue = 0;
float counter = 0.00;
for (int x = -1; x < 2; x++)
{
for (int y = -1; y < 2; y++)
{
int X = i + x;
int Y = j + y;
if (X < 0 || Y < 0 || X > (height - 1) || Y > (width - 1))
{
continue;
}
totalRed += image[X][Y].rgbtRed;
totalGreen += image[X][Y].rgbtGreen;
totalBlue += image[X][Y].rgbtBlue;
counter++;
}
tmp[i][j].rgbtRed = round(totalRed / counter);
tmp[i][j].rgbtGreen = round(totalGreen / counter);
tmp[i][j].rgbtBlue = round(totalBlue / counter);
}
}
}
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
image[i][j].rgbtRed = tmp[i][j].rgbtRed;
image[i][j].rgbtGreen = tmp[i][j].rgbtGreen;
image[i][j].rgbtBlue = tmp[i][j].rgbtBlue;
}
}
return;
}
I'm trying to create a char matrix using dynamic allocation (char**). It represents a board where the margins are '#' character and in the middle is the ASCII 32 (blank space). When I run the code this massage appear: "Exception thrown at 0x00007FFD9ABF024E (ucrtbased.dll) in myapp.exe: 0xC0000005: Access violation reading location " in some cpp file.
Here's my code:
#include <iostream>
using namespace std;
char** allocateBoard(int n)
{
char** Board = 0;
Board = new char* [n+2];
int i;
for (i = 0; i < n + 2; i++)
{
Board[i] = new char[n * 2 + 2];
}
return Board;
}
void initBoard(char**& Board, int n)
{
int i, j;
for (i = 0; i < n; i++)
{
for (j = 0; j < n * 2; j++)
{
if (i == 0 || i == n - 1) Board[i][j] = '#';
else if (j == 0 || j == n * 2 - 1) Board[i][j] = '#';
else Board[i][j] = 32;
}
}
}
void showBoard(char** Board, int n)
{
int i, j;
for (i = 0; i < n; i++)
{
for (j = 0; j < n * 2; j++)
{
cout << Board[i][j];
}
cout << endl;
}
}
int main()
{
int n = 4;
char** Board = 0;
Board = allocateBoard(n);
initBoard(Board, n);
showBoard(Board, n);
cout << endl;
showBoard(Board, n);
for (int i = 0; i < n * 2 + 4; i++)
{
delete[] Board[i];
}
delete[] Board;
return 0;
}
Does anyone know where is the problem? As a very beginner I can't see where is the mistake. I've allocated more space in the matrix than I'm actually using so I can't figure why this message appears. Is the deallocation the problem?
Thanks!
Example, previous low is 1.55. When next candle low is 1.66, then next next candle low is 1.44 which is lower than previous low (1.55) then do something. How to achieve it?
double previous_low = 0;
double new_low = 0;
double new_low2 = 0;
if (((previous_low==0)&&(Low[1] < Low[2])){
previous_low = Low[1];
}
if (previous_low != 0){
if (Low[1] < previous_low){
new_low2 = Low[1]; //it fail
}
if (Low[0] < previous_low){
new_low2 = Low[0]; //it works only if next 1 candle is lower than previous. It fail if next 2 candle is lower than previous_low.
}
}
It can be achive by bubblesort
public class BubbleSort
{
void bubbleSort(double arr[])
{
int n = arr.length;
for (int i = 0; i < n-1; i++)
for (int j = 0; j < n-i-1; j++)
if (arr[j] > arr[j+1])
{
System.out.print("first value :"+arr[j]+" greater than" +"previos :"+arr[j+1] + " ");
System.out.println();
// swap arr[j+1] and arr[i]
double temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
/* Prints the array */
void printArray(double arr[])
{
int n = arr.length;
for (int i=0; i<n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver method to test above
public static void main(String args[])
{
BubbleSort ob = new BubbleSort();
double arr[] = {1.66, 1.55, 1.44};
ob.bubbleSort(arr);
System.out.println("Sorted array");
ob.printArray(arr);
}
}
I am currently implementing a connected components algorithm and the last step of the algorithm requires me to enclose the objects I found in a box. I have attempted to enclose an object in a box and this is the result:
As you can see some of them seem to be enclosed in a box. Some of the lines of the box are not seen unless I stretch the windows of the imshow function's output and also some of them have color when I expected a line with a shade of gray.
My question is: Is the object really getting enclosed since I remember when I ran a similar code of mine into a different OS the lines with color are not see at all but are seen in my computer. Additionally, why are some of the lines in a different color given that I was expecting a shade of gray.
Mat src, src_gray;
Mat dst, detected_edges;
const char* window_name = "THRESHOLDED IMAGE";
/**
* #function connectedComponent
*/
static void connectedComponent(int, void*)
{
Mat test; //dummy
Mat sub;
int newObject = 0;
int zeroTest = 0, nonZero = 0;
int arr[5] = {0,0,0,0,0};
/// Reduce noise with a kernel 3x3
blur( src_gray,detected_edges, Size(3,3) ); //filtering out of noise
namedWindow("INITIAL", WINDOW_NORMAL);
imshow("INITIAL",detected_edges);
resizeWindow("INITIAL", 300, 300);
threshold(detected_edges, detected_edges, 0,255, THRESH_BINARY | THRESH_OTSU);
int** newSub = new int*[detected_edges.rows];
for(int i = 0; i < detected_edges.rows; i++)
newSub[i] = new int[detected_edges.cols];
for(int i = 0; i < detected_edges.rows; i++){
for(int j = 0; j < detected_edges.cols; j++){
newSub[i][j] = 0;
}
}
/*INITIAL MARKING LOOP*/
for(int i = 0; i < detected_edges.rows; i++){
for(int j = 0; j < detected_edges.cols; j++){
if(detected_edges.at<uchar>(i,j) == 0){
if(i-1 < 0 && j-1 < 0){
newObject = newObject + 1; //no values
newSub[i][j] = newObject;
}else if(i-1 >= 0 && j-1 < 0){
if(newSub[i-1][j] != 0){
newSub[i][j] = newSub[i-1][j]; //only up has value
}else{
newObject = newObject + 1; //no values
newSub[i][j] = newObject;
}
}else if(i-1 < 0 && j-1 >= 0){
if(newSub[i-1][j] != 0){
newSub[i][j] = newSub[i-1][j]; //only left has value
}else{
newObject = newObject + 1; //no values
newSub[i][j] = newObject;
}
}else{
if(newSub[i-1][j] == 0 && newSub[i][j-1] == 0){
newObject = newObject + 1; //no values
newSub[i][j] = newObject;
}else if(newSub[i-1][j] == newSub[i][j-1]){ //same value
newSub[i][j] = newSub[i-1][j];
}else if((newSub[i-1][j] != 0 && newSub[i][j-1] == 0)){
newSub[i][j] = newSub[i-1][j]; //only up has value
}else if(newSub[i-1][j] == 0 && newSub[i][j-1] != 0 ){
newSub[i][j] = newSub[i][j-1]; //only left has value
}else if(newSub[i-1][j] != newSub[i][j-1]){
newSub[i][j] = newSub[i-1][j]; //different values follow upper's value
}
}
}
}
}
int a = 1;
int maxRows = detected_edges.rows;
int maxCols = detected_edges.cols;
/*CONNECTING PIXELS RIGHT-BOTTOM*/
while(a < newObject){
int update = 0;
for(int i = 0; i < maxRows; i++){
for(int j = 0; j < maxCols; j++){
if(newSub[i][j] == a){
if(i+1 < maxRows && j+1 < maxCols){
if(newSub[i][j+1] > a){ //both points allowed
int value = newSub[i][j+1]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){
if(newSub[h][k] == value){ //replace all instances of that value
newSub[h][k] = a;
}
}
}
update = 1;
}
if(newSub[i+1][j] > a){ //both points allowed
int value = newSub[i+1][j]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){
if(newSub[h][k] == value){
newSub[h][k] = a; //replace all instances of that value
}
}
}
update = 1;
}
}else if(i+1 > maxRows && j+1 < maxCols){
if(newSub[i][j+1] > a){ //bottom is not allowed
int value = newSub[i][j+1]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){
if(newSub[h][k] == value){
newSub[h][k] = a; //replace all instances of that value
}
}
}
update = 1;
}
}else if(i+1 < maxRows && j+1 > maxCols){
if(newSub[i+1][j] > a){ //right is not allowed
int value = newSub[i+1][j]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){
if(newSub[h][k] == value){ //replace all instances of that value
newSub[h][k] = a;
}
}
}
update = 1;
}
}
}
}
}
a++;
}
/*CONNECTING PIXELS LEFT-TOP*/
a = newObject;
while(a > 0){
int update = 0;
for(int i = maxRows-1; i > 0; i--){
for(int j = maxCols-1; j > 0 ; j--){
if(newSub[i][j] == a){
if(i-1 >= 0 && j-1 >= 0){
if(newSub[i][j-1] > a){ //both points allowed
int value = newSub[i][j-1]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){
if(newSub[h][k] == value){
newSub[h][k] = a;
}
}
}
update = 1;
}
if(newSub[i-1][j] > a){
int value = newSub[i-1][j]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){
if(newSub[h][k] == value){ //replace all instances of that value
newSub[h][k] = a;
}
}
}
update = 1;
}
}else if(i-1 >= 0 && j-1 < 0){
if(newSub[i][j-1] > a){ //left is not allowed
int value = newSub[i][j-1]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){ //replace all instances of that value
if(newSub[h][k] == value){
newSub[h][k] = a;
}
}
}
update = 1;
}
}else if(i-1 < 0 && j-1 >= 0){
if(newSub[i-1][j] > a){ //top is not allowed
int value = newSub[i-1][j]; //get the value I need to replace
for(int h = 0; h < maxRows; h++){
for(int k = 0; k < maxCols; k++){ //replace all instances of that value
if(newSub[h][k] == value){
newSub[h][k] = a;
}
}
}
update = 1;
}
}
}
}
}
a--;
}
for(int i = 0; i < maxRows; i++){
for(int j = 0; j < maxCols; j++){
int check = 0;
if(newSub[i][j] != 0){
for(int k = 0; k < 5; k++){
if(newSub[i][j] == arr[k]){ //check if there is an instance of the value in the given array of values
check = 1;
break;
}
}
if(check == 0){
for(int r = 0; r < 5; r++){
if(arr[r] == 0){
arr[r] = newSub[i][j]; //if new value is found add to array
break;
}
}
}
}
}
}
/*
I HAVE AN ARRAY CONTAINING ALL VALUES
**/
src.copyTo( sub, detected_edges);
sub = Scalar::all(0);
/*SET AN INTENSITY FOR CORRESPONDING VALUES*/
int intensity = 50;
a = 0;
while(a < 5){
int update = 0;
for(int i = 0; i < maxRows; i++){
for(int j = 0; j < maxCols; j++){
if(newSub[i][j] == arr[a]){
sub.at<uchar>(i,j) = intensity;
}
}
}
a++;
intensity = intensity + 50;
}
a = 250;
/*GETTING MIN-MAX COORDINATES*/
while(a >= 50){
int setter = 0;
int minRow = 0;
int minCol = 0;
int maxRow = 0;
int maxCol = 0;
for(int i = 0; i < maxRows; i++){
for(int j = 0; j < maxCols; j++){
if(sub.at<uchar>(i,j) == a){
if(setter == 0){
minRow = i;
minCol = j;
maxRow = i;
maxCol = j;
setter = 1;
}else{
if(i <= minRow){
minRow = i;
}
else{
if(i > maxRow){
maxRow = i;
}
}
if(j <= minCol){
minCol = j;
}
else{
if(j > maxCol){
maxCol = j;
}
}
}
}
}
}
/*THIS IS WHERE I MAKE MY BOUNDING BOX*/
for(int i = minRow; i < maxRow; i++){
sub.at<uchar>(i,minCol) = 255; //set up the horizontal lines
sub.at<uchar>(i,maxCol) = 255;
}
for(int i = minCol; i < maxCol; i++){
sub.at<uchar>(minRow,i) = 255; //set up the vertical lines
sub.at<uchar>(maxRow,i) = 255;
}
a = a - 50;
}
dst = Scalar::all(0);
src.copyTo( dst, detected_edges);
imshow( window_name, dst );
namedWindow("FINAL", WINDOW_NORMAL);
imshow("FINAL",sub); //final output
resizeWindow("FINAL", 300, 300);
for(int i = 0; i < detected_edges.rows; i++)
delete[] newSub[i];
delete[] newSub;
}
/**
* #function main
*/
int main( int, char** argv )
{
/// Load an image
src = imread( argv[1] );
if( src.empty() )
{ return -1; }
/// Create a matrix of the same type and size as src (for dst)
dst.create( src.size(), src.type() );
/// Convert the image to grayscale
cvtColor( src, src_gray, COLOR_BGR2GRAY ); //grayscale for one channel for easy computation
/// Create a window
namedWindow( window_name, WINDOW_NORMAL );
resizeWindow(window_name, 300,300);
/// Show the image
connectedComponent(0, 0);
/// Wait until user exit program by pressing a key
waitKey(0);
return 0;
}
I've been following a tutorial to try and wrap my head around Dijkstra's shortest path algorithm. Originally it was in Java, but I tried my best to switch it over to C++, but unfortunately I've run into a problem that I can't seem to fix.
here's my code
The error happens in the line
---Distancearray[0] = Testarray[0];
#include <iostream>
using namespace std;
int main(){
int Testarray[5][5] = {{}};
//stores first row of test array
//updates when visiting nodes
int Distancearray[5] = {};
//stores visited nodes
int visitedN[5] = {};
//stores previous node
int PreviousN[5] = {};
//holds the minimum value
int Min = 999999;
//holds the next node value
int NextNode = 0;
cout << "Enter Numbers:\n" << endl;
for(int i=0; i < 5; i++){
//initialize visited array to 0
visitedN[i] = 0;
//same
PreviousN[i] = 0;
for(int j=0; j < 5; j++){
cin >> Testarray[i][j];
if(Testarray[i][j] == 0){
//sets the largest possible number
Testarray[i][j] = 999999;
}
}
}
Distancearray[0] = Testarray[0];
//Sets source node as checked
visitedN[0] = 1;
//Sets distance from sources to 0, starting point
Distancearray[0] = 0;
for(int i=0; i<5; i++){
Min = 9999999;
for(int j = 0; j<5 ; j++){
if(Min > Distancearray[j] && visitedN[j] != 1){
//sets next node to J
Min = Distancearray[j];
NextNode = j;
}
}
visitedN[NextNode] = 1;
for(int i=0; i<5; i++){
if(visitedN[i] != 1){
if(Min+Testarray[NextNode][i] <= Distancearray[i]){
Distancearray[i] = Min+Testarray[NextNode][i];
PreviousN[i] = NextNode;
}
}
}
}
for(int i=0; i<5; i++){
cout << "Lenght" + Distancearray[i] << endl;
}
for(int i=0; i<5; i++){
int j;
cout <<"Path:" + i << endl;
j=i;
do{
j = PreviousN[j];
cout<<"<---" + j<<endl;
}
while(j!=0);
}
return 0;
}
any thoughts?