but i want to write app in cpp and make use of some API written fully as a python module

Hi, what's the best way to embed python module or at least some code into c++ code? Unfortunately the python codebase is simply too big and rewriting it would be an overkill.

To print string

https://docs.python.org/3/extending/embedding.html I have not done it but I guess official documentation is what you are looking for. Alternatively you can experiment with Boost.Python

Yeah, I've gone through python docs. Just asking here because maybe there's a better method

what stops you from just doing std::cout << ch?

Boost.Python?

what stops you from just doing std::cout << ch?

also i'd like to use it in a c++ qt app if it makes any difference

But why loop is not working

I have no idea as I havent ever tried doing that.

It is not working because your for loop is: for(int i=0; i != 0; ++i) Since i!=0 condition fails before the loop body is executed, nothing is printed. If you must use a loop, you can do: char* p = ch; while(*p) cout << *p++;

Fair. I'll compare Python/C API with Boost and if they will be more problematic than helpful then I'll write everything in python. Thanks for your support! :)

look at this too https://cffi.readthedocs.io/en/latest/index.html https://cffi.readthedocs.io/en/latest/overview.html#embedding

Pls why does this code say Segmentation fault?? #include <stdio.h> int main(char *dest, char *src) { int index; int len1 = 0, len2 = 0; dest = "osei"; src = "richard"; while(*dest++) len1++; while(*src++) len2++; for (index = 0; index<=len2; index++) { dest[len1 + index] = src[index]; } printf("%s", dest); }

I think too you're changing dest and src w/ your ++ arg so by the time they get referenced again it's beginning at the terminator rather than the start of your string

Can I get the link to download C/C++ software

Can I get the link to download C/C++ software

The best way to learn is via a book because they cover it in depth

if i declare vector<vector<int>> ans; and then use resize(), it doesn't work if i assign a default size: vector<vector<int>> ans(n); and then use resize() it works Why?

String & operator= (construction string &other) what's meaning of this method?

When you say something works or doesn't work, tell us what you did to check that it doesn't work. Learn how to ask questions. Usually showing code where you do the checking will suffice. We don't have crystal balls here to predict what you did or want to do

wrote this code for pascal's triangle: vector<vector<int>> generate(int numRows) { vector<vector<int>> ans(numRows); for(int i=0; i<numRows; i++){ ans[i].resize(i+1); // first and last values are always 1 ans[i][0] = 1; ans[i][i] = 1; for(int j=1; j<i; j++){ ans[i][j] = ans[i-1][j-1] + ans[i-1][j]; } } return ans; } It works But when I do vector<vector<int>> ans; and try to resize it, it doesn't

I need a channel in YouTube it, s a best

It is the assignment operator. Used when you assign one string to another

this piece of code runs well on online ide but not on my visual Studio Code

#include<iostream> #include<queue> using namespace std; class Node { public: int data; Node *left; Node *right; Node(int d) { data=d; } }; Node* insert(Node *root,int val) { if(root==NULL) { root=new Node(val); return root; } if(val<=root->data) { root->left=insert(root->left,val); return root; } else if(val>=root->data) { root->right=insert(root->right,val); return root; } } Node* build() { int d; cin>>d; Node *root=NULL; while(d!=-1) { root=insert(root,d); cin>>d; } return root; } Node* searchInBST(Node *root,int key) { if(root==NULL) { return NULL; } if(root->data==key) { return root; } if(key<root->data) { return searchInBST(root->left,key); } return searchInBST(root->right,key); } void bfs(Node *root) { if(root==NULL) { return; } queue<Node*> q; q.push(root); q.push(NULL); while(!q.empty()) { Node *f=q.front(); if(f==NULL) { cout<<endl; q.pop(); if(!q.empty()) { q.push(NULL); } } else { q.pop(); cout<<f->data<<" "; if(f->left) { q.push(f->left); } if(f->right) { q.push(f->right); } } } } void inorder(Node *root) { if(root==NULL) { return; } inorder(root->left); cout<<root->data<<" "; inorder(root->right); } int main() { Node *root=NULL; root=build(); bfs(root); cout<<endl; inorder(root); cout<<endl; cout<<searchInBST(root,6)->data; return 0; }

When you say it doesn't run, you mean it crashes or gives a wrong answer?

In your insert function you don't return anything if you find a node with the same value as val. This can result in UB.

#include<iostream> #include<queue> using namespace std; class Node { public: int data; Node *left; Node *right; Node(int d) { data=d; } }; Node* insert(Node *root,int val) { if(root==NULL) { root=new Node(val); return root; } if(val<=root->data) { root->left=insert(root->left,val); return root; } else if(val>=root->data) { root->right=insert(root->right,val); return root; } } Node* build() { int d; cin>>d; Node *root=NULL; while(d!=-1) { root=insert(root,d); cin>>d; } return root; } Node* searchInBST(Node *root,int key) { if(root==NULL) { return NULL; } if(root->data==key) { return root; } if(key<root->data) { return searchInBST(root->left,key); } return searchInBST(root->right,key); } void bfs(Node *root) { if(root==NULL) { return; } queue<Node*> q; q.push(root); q.push(NULL); while(!q.empty()) { Node *f=q.front(); if(f==NULL) { cout<<endl; q.pop(); if(!q.empty()) { q.push(NULL); } } else { q.pop(); cout<<f->data<<" "; if(f->left) { q.push(f->left); } if(f->right) { q.push(f->right); } } } } void inorder(Node *root) { if(root==NULL) { return; } inorder(root->left); cout<<root->data<<" "; inorder(root->right); } int main() { Node *root=NULL; root=build(); bfs(root); cout<<endl; inorder(root); cout<<endl; cout<<searchInBST(root,6)->data; return 0; }

You are assuming the node you are seraching for will always be present. If it is not present then the line cout << searchInBST(root, <value>)->data; will throw an exception. Otherwise the code should run fine based on a cursory glance. And learn to use a debugger. This is probably the 3rd time I am telling you this. Without knowing how to use a debugger, you cant go much further

You are assuming the node you are seraching for will always be present. If it is not present then the line cout << searchInBST(root, <value>)->data; will throw an exception. Otherwise the code should run fine based on a cursory glance. And learn to use a debugger. This is probably the 3rd time I am telling you this. Without knowing how to use a debugger, you cant go much further

You are assuming the node you are seraching for will always be present. If it is not present then the line cout << searchInBST(root, <value>)->data; will throw an exception. Otherwise the code should run fine based on a cursory glance. And learn to use a debugger. This is probably the 3rd time I am telling you this. Without knowing how to use a debugger, you cant go much further

Oh okay okay thanks

But then what can be the reason due to which it's running on online ide and not on visual studio code

Yea you have told me previously to use a debugger. I'll try to use it from now on. Actually I thought it's not a good practice to use debugger to find errors.

Whoever gave you that idea is wrong. Debuggers are one of the most important tools in a software developer's toolbox

Ok thanks.

how ?

#include<iostream> #include<queue> using namespace std; class Node { public: int data; Node *left; Node *right; Node(int d) { data=d; } }; Node* insert(Node *root,int val) { if(root==NULL) { root=new Node(val); return root; } if(val<=root->data) { root->left=insert(root->left,val); return root; } else if(val>=root->data) { root->right=insert(root->right,val); return root; } } Node* build() { int d; cin>>d; Node *root=NULL; while(d!=-1) { root=insert(root,d); cin>>d; } return root; } Node* searchInBST(Node *root,int key) { if(root==NULL) { return NULL; } if(root->data==key) { return root; } if(key<root->data) { return searchInBST(root->left,key); } return searchInBST(root->right,key); } void bfs(Node *root) { if(root==NULL) { return; } queue<Node*> q; q.push(root); q.push(NULL); while(!q.empty()) { Node *f=q.front(); if(f==NULL) { cout<<endl; q.pop(); if(!q.empty()) { q.push(NULL); } } else { q.pop(); cout<<f->data<<" "; if(f->left) { q.push(f->left); } if(f->right) { q.push(f->right); } } } } void inorder(Node *root) { if(root==NULL) { return; } inorder(root->left); cout<<root->data<<" "; inorder(root->right); } int main() { Node *root=NULL; root=build(); bfs(root); cout<<endl; inorder(root); cout<<endl; cout<<searchInBST(root,6)->data; return 0; }

In Insert if(val<=root->data) { root->left=insert(root->left,val); return root; } If val == root->data, you will insert this val again in the left tree. If you are not going to ever search for this node, what is the point of inserting it in the tree? This insert will matter in cases where your nodes may have the same key but have some other data where these nodes may differ. Like I said earlier, it doesnt matter in your simple example. In searchInBST if(key<root->data) { return searchInBST(root->left,key); } return searchInBST(root->right,key); Here, if suppose searching were based on both key and other data, then your if condition should be if (key <= root->data)

Whoever gave you that idea is wrong. Debuggers are one of the most important tools in a software developer's toolbox

That shouldn't be a problem because even if the value is equal to root->data I make a call to insert in the tree rooted at root->left

Ah I see, then you could just use else without additional check.

right?

yes. I use GDB mostly. If you are using Visual Studio, search for its documentation or go to Youtube and search for tutorial videos

Exception thrown at 0x004014AD in buildBST.exe: 0xC00000FD: Stack overflow (parameters: 0x00000001, 0x00422FFC). how to know which line of code it is talking about

Exception thrown at 0x004014AD in buildBST.exe: 0xC00000FD: Stack overflow (parameters: 0x00000001, 0x00422FFC). how to know which line of code it is talking about

use a sanitiser

Set a break point in your code and step through line by line using a debugger. On GDB, I can usually get a backtrace to see where the exception was thrown and read the data at that point of time to see what the problem was. I can also analyze the core file. Visual Studio should also have support for it (not the core file though)

I don't know that either 😅

add -fsanitze=address to the compilation command (works on gcc and clang. check documentation for MSVC, you might also need to install the component separately). run the program as before. it will give colourful details of the stack overflow.

Do you mean in the terminal add this command?

https://devblogs.microsoft.com/cppblog/address-sanitizer-for-msvc-now-generally-available/

I'll go through these terms now