C :: Pointers And String Manipulations - Finding Correct Path
Mar 11, 2014
i've been writing some code for an assignment and it is mostly about pointers and string manipulations. It runs but crashes and I think it might be from over- valuating some strings maybe not. I have written in check points to make sure each function passes through but quits at findFirstPath loop, I had kept running the program through as i added more and more code. It had stopped when I near finished I believed it to just be because I hadn't finished the functions I called.
I am new to Path Finding so I just know BFS, DFS, Djisktra, and Basic A*
I've searched for a few multi agent pathfind paper here and there. But I can't seem to understand them..
I am path finding in a grid map, 4 ways neighbor movement
My map isn't so big it's 300 x 300 up to 400 x 400
Most of the map is open space, I would say that at worst case 4/5 of the map is open space.
And there is probably around 100 agents.
I've tried running BFS 100 times and it takes around 200ms on average
Changing BFS to A* which I am thinking right now will definitely cost lesser time
But are there better ways in doing this ? and also Does running Single Agent A* multiple times doesn't cause problem for other agent ? perhaps causes deadlocks ? ( Considering that the path that have been determine for agents before the current searched is considered blocked )
I was asked to find the longest path in a graph. I was thinking about using Dijsktra's algorithm after multiplying all the weights with -1 and run the program in normal way and find the shortest path. And then I'll multiply with -1 again and get the longest path. I think this should give me the longest path, do you think it would work? And also, I'm dealing with considerably big data, such as 1.000.000 nodes and many more edges. etc. and I have a time limit of 2 seconds and memory limit of 128mb. Any other data structure instead of Adjacency Matrix? Because I'm pretty sure it will exceed the limits.
I've been trying to make a program to return node values for the shortest path from one node to another. I've searched up several algorithms like the Bellman Ford, A*, or Dijkstra and tried to think of ways to implement them if I store my map as a matrix. I've considered using a hash table, but since I am only a beginner, I am having trouble trying to understand how the concepts would translate into C.
I have my application database in the AppDataRoaming folder. I'm trying to create a connection string for Telerik reporting, up until now I've had a connection string in a settings class that is put together like this:
The path is:
data source=C:UsersSynlightAppDataRoamingAppNamedataAppDB.sqlite
I want to program an advanced calculator. I'd like to enter some more complex expressions like -17+3*4*(4-sqrt(4) and i want, that mathematical operations are done the correct order, so at first 4-sqrt(4) is calculated, then 3*4*2 and then -17 is subtracted.
Problem 1: Convert a string into a mathematical calculation Problem 2: Calculate in the correct order
How would I do that (I dont expect perfecly precoded calculators from you, just the way how to do it)
Google search just delivers primitive calculations with entry methods like
Enter first number 1 Enter operator + Enter second number 2
This for loop replaces the stars ******** in an array that contains a word to be guessed with the correct letter (c) that the user inputs if the word contains that letter.
Problem: After every guess the same hidden string of stars ******* is displayed instead of ex: ***W**** (assuming W was entered by the user)
How can I update the old ******** string in the Stars array with the new string that includes the correct letters chosen, so after every correct guess at a letter in the word a new string is displayed including the correct letters chosen?
I'm pretty sure I have to use strcpy but not sure how to implement it using a loop.
Code: for(i = 0; i < strlen(unscrambledWord); i++) { if(unscrambledWord [i] == c) { Stars[i] = c; } }
When I do this after function copies bb to the array it puts '' ? I mean last for array would be 'b' 'b' 'a' '' or 'b' 'b' '' ''. I am trying to learn the basics of searching a string, finding and changing them with another string.
i just want to check to see if one word (string) or one sentance is equal to any others within an array. My code
so basically i want to check if a is equal to either "sleep", "in", or "bed". Or even if the string within a is equal to "sleep in bed" as one string.
I have used the following but even if i get it correct and it says correct it says incorrect another 2 times because it is saying yeah you have gotten one right out of the possible 3. Even if I type "sleep in bed" it still does it (prints out incorrect another 2 times. Also are there any good books to start off with c++?
#include <iostream> #include <string> #include <iomanip> using namespace std; int main() { //Program Goal //Have 3 Strings to represent 3 categories //Have the user type in their name //Have the user type in a full sentence how they are feeling //Program should find the word in the user inputted sentence and display an appropriate response
I am trying to take a string that is within the main function, and write a void function that gives me the most common alpha character used inside the string. How to mix a string and an array together like that as I am not too familiar with arrays yet.
I want to find that whether the 2d Vector table having duplicate or not. I can see lot of programs for removing duplicates by using unique STL algorithm. Which is the best way to find " is Duplicate or not " for 100,000 Records.
I know how to find the occurrences of a character in a string, but I have a more specific problem.
For example, consider the string: " C 1.3825 4.0000 12.0000 1.9133 0.1853 0.9000 -1.1359 4.0000 "
I want to extract a vector that contains the positions of every first character for each number.
For the example above, the output should be a vector with elements [6 15 23 33 etc...]. These are the positions of the first character for every number.
I need to be able to do this for any arbitrary string with any arbitrary amount of numbers and characters in it (I also need to account for negative numbers).
i couldnt solve the algorithm exactly. The program asks the user for a string. "Bugun h@v@ cok g'uzel" for example. then the program asks for another string. If that string doesnt exists in the main string program should say there isnt any substring. If it exist then the program should print the remaining part of main string. For example:
Write the first string: Tod@y weather is be'@utiful write the substring : ug >>ugun h@v@ cok guzel write the substring :wldnqwbdbj >>there isnt any substring Here where i came so far
#include <stdio.h> int main() { char mainstr[50],substr[50];
bool isUnique(string _str) { bool char_set[256]; int len = _str.length(); memset(char_set, '/0', 256); for(int i = 0; i < len; ++i)
[Code] .....
I came across this code to find if string has unique characters...i didnt understand why they subracted ascii value of character '0' in the statement int val = _str[i]- '0' and what is happening with the statements...
I take each character in the sting and traverse the whole string .and if count is 2 i use break and conclude that its not unique and not otherwise...can i use this method or this is not efficient????
the code shows all characters frequency, however i want to find which one has highest frequency for example cprogrammmmming cboard highest frequency: m
char string[100], ch;int c =0, count[26]={0}; printf("Enter a string"); gets(string);
Having some trouble with basic stuff while learning C. My purpose was to flip the pointing order, so it would point to the string from the end to the start. didn't work so well using **str as well.
My teacher has done a very poor job of teaching us anything this year. When he taught us for loops, he wrote one on the board, didn't explain any of it, then said now that you know for loops we can implement them in a code. but anyway, we need to write a code for converting a string to an int and all the examples i find on the internet use pointers but we aren't allowed to use those yet.
Problem: I have to find the word "NAND" and then find the numbers inside the brackets because they are the inputs to that NAND gate. I have written a code below but that code can detect the fixed number of inputs. I need a code which can detect any number of inputs (whether 2 inputs or more than two). But i don't understand how do i do that?
My code:
Code: string input_str ("INPUT"), output_str ("OUTPUT"), nand_str("NAND"); while (getline( input_file, line )) { std::size_t guard_found = line.find(guard_str);
I have a little problem with one of my functions. The function purpose is to get a number (n) and create an array (size n) with pointers to strings (each string length is 20 chars) and i don't know why but during the debugging i get a <bad ptr> message and this message :
CXX0030: Error: expression cannot be evaluated
This is my function:
Code: char** getlist(int n) { int i=0; char **arr; arr=(char**)malloc(sizeof(char)*n); if (arr==NULL)
The snippet below (or similar) compiles and runs OK but I am using Visual Studio C++ compiler. Are the lines where .nameFirst and .nameLast assigned kosher in ANSI C?
Also I am concerned about the memory allocation for these string constants. Does the runtime system put them on the heap? It doesn't seem that they are really constants since they are not defined before runtime.
