I have a very simple program the time complexity of the function that I used in this program is O(mn)because it has a nested loop, I really need to reduce the time complexity to O(n)
[code=c++]
#include <iostream.h>
#include<stdlib.h>
int *char_count( const char* DNA, const int *starts, const int *ends, char letter);
int main()
[Code].....
define the time and space complexity of an algorithm and about what can i do when the time and space complexity are given and i should write the code corresponding to the restrictions , which i find very difficult.
View 1 Replies View RelatedWe were discussing how to find average time complexity of different algorithms. Suppose I've a the following nested loop
for(int i=0;i<n;i++)
{
min = i;
[Code].....
Now the outer loop will iterate N times. the inner loop will always iterate 3 times no matter what the value of N is. so the worst case time complexity should be O(n^2) but what about the average case and the best case? I mean in terms of searching we can figure out and distinguish between the worst,best and average as it depends upon the number of comparisons. But here how can the average and best case be different then the worst case.
I am using
#include <vector>
#include <map>
In my c++ project, and these 2 header files are included in almost 200 .cpp files and when i build a static library for the whole project in linux its size is around 10MB and when i did the same thing in windows its size is almost over 80MB, and one thing i noticed was both vector and map combinely takes 500KB in each .cpp file in windows. I am building the static library in windows using release mode.
I am using VS 2007. Any way to reduce the library size.
I am looking at reducing the size of a compiled executable for easier distribution.
What factors affect the size of an output executable?
Would literally having defined and implemented less functions, would make the exec. smaller? Meaning that instead of have a DLL ( yes im on windows ), I would download the source code of a library and comment out the functions ( and code ) that I am not using -- Would this process decrease the size of my exec.?
Have an assignment due in a few weeks and I'm 99% happy with it My question is is there a method or process for reducing redundant code in nested loops. Ie my code compiles and runs as expected for a period of time and after a few goes it omits a part or prints an unexpected out ext so basically how to find when the redundancy occurs with out posting my code so I can learn for my self?
View 3 Replies View RelatedWhat would the worst, average and best case space complexity be for a data structure of type map<string, vector<int> > in big O notation? I'm parsing through a document and storing each word as a key and im attaching an associated int (in a vector) to it as the value.
View 4 Replies View RelatedFor the following code :
s = 0 ;
for(i=m ; i<=(2*n-1) ; i+=m) {
if(i<=n+1)
{ s+=(i-1)/2 ; }
else
{ s+=(2*n-i+1)/2 ; }
}
I want to change the complexity of the code from O(n) to O(1) . So I wanted to eliminate the for loop . But as the sum "s" stores values like (i-1)/2 or (2*n-i+1)/2 so eliminating the loop involves tedious calculation of floor value of each (i-1)/2 or (2*n-i+1)/2 . It became very difficult for me to do so as I might have derived the wrong formula in sums of floors . Need Changing complexity from O(n) to O(1). Is there any other way to reduce the complexity ? If yes ... then how ?
Assuming that we have :
Code:
int arr2d[rows][columns] ; // Not valid syntax of course ... let be arr2d rows * columns size
for(int i=0; i<rows; i++)
for(int j=0; j<columns; j++)
arr2d[rows][columns] = some_value;
What is the complexity? I believe O(n) and not O(n^2) on this case because if you have 3*3 size you would put 9 elements (from 9 elements input of course)... for each input you have one insertion and that is the meaning. Same as 4*4 size 16 input times 16 insertions .. or 5*5 and so forth...
Giving a dynamic array, we want to pass the array elements from a file. The first number in the file N gives us the array length. They follow N numbers, the actual elements of the array.
Three brothers are going to work in the shop of their father for a time. The shop is doing well and every day generates profit which the three brothers may provide. The brothers agreed that they would divide the total time in three successive parts, not necessarily equal duration, and that each one will be working in the shop during one of these parts and collects the corresponding profit on his behalf. But they want to make a deal fairly, so that one received from three more profit someone else. Specifically, they want to minimize the profit the most favored of the three will receive.
I first created a program that WORKS! with complexity O(n3).
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
int sum_array(int* array, int cnt){
int res = 0;
int i;
for ( i = 0; i < cnt ; ++i)
[Code] .....
Let's assume that we have the following input:
10
1 1 8 1 1 3 4 9 5 2
The ouptut should be 15 -> A = 1 + 1 + 8 + 1 + 1 + 3 = 15 , B = 4 + 9 = 13 , C = 5 + 2 = 7.
But the ouptut is 16!
How can I reduce the complexity of my first working! C code?
this function has to check if an array is not descending it has to be recursive and it's space complexity has to be O(log(n))
Code:
int is_sorted(int a[ ], int n) {
int check=n-1;
if(n==1 || n==0) return 1;
if(a[check]<a[check-1])return 0;
else return(is_sorted(a,n-1));
}
this is what i came up with. i know it's space complexity is O(n) how do i make it O(log(n))?
I was just going through Radix Sort algorithm. Though I got the logic and the concept used in it, I am still pretty much confused about the space complexity being O(k+n) for this algorithm. (where, k is the max no of digits in a number, and n is the no. of inputs to be sorted).
View 1 Replies View Relatedwould like to know that my algorithm has asymptotic complexity recursive?
int solve(pair<int,int> actual)
{
if(actual.first == PuntoInicio.first && actual.second == PuntoInicio.second)
return 1;
[Code]....
Suppose you have a switch statement defined like:
switch (parameter) {
case ONE:
case TWO:
// ... other n-2 cases
case N:
doSomething();
break;
default:
somethingElse();
break;
}
What is the complexity of the doSomething()? Is it still equal to the complexity of doSomething() , or the complexity of doSomething() plus the number of case statements? In other words, does the number of case statements a conditional piece of code has count towards the complexity?
This is a round robin execution. with gantt chart. arrival time and burst time. I think there is an error in my formula to get the right answer,i cant resolve it but my program is running. What is the code or the right formula??
#include<stdio.h>
int main(){
int i,j=0,n,time,remain,flag=0,ts;
int sum_wait=0,sum_turnaround=0,at[10],bt[10],rt[10];
int ganttP[50],ganttStartTime[50];
printf("Enter no of Processes : ");
scanf("%d",&n);
remain=n;
[Code] ....
I have a class 'A' which is almost perfect for my needs. Class 'B' uses class 'A' I've now designed Class 'C' and Class 'D' and noticed that there is a good chunk of code in class 'B', 'C' and 'D' for using Class 'A' is duplicated. I've separated out this code in specific, standalone functions in each of the classes. Now I'm wondering where this code should go. At the moment, the functions are duplicated in the three calling classes (B, C and D). Placing the functions into class 'A' would break the single responsibility principle. Inheritance to add functionality would likely break both SRP and LSP. The one that seems that it may work is composition.
However, Is designing a complete class just for a few functions over kill?
Would it be valid for classes 'B', 'C' and 'D' to access both the new class 'E' (which would depend on A) and the old class 'A' (which would have to be the same instance as the instance in the new class 'E'), or should the new class 'E' provide sufficient functionality so that Classes B, C and D don't need to access Class A directly? It would seem that its then an incomplete interface of the original object with additional functionality (ie, incompatible) Or should I do it a completely different way?
So I'm trying to learn how to use time for time based movement and what not. I did this only knowing the command time(&variable)
time_t timer;
int I, X;
void main() {
time(&timer);
X=timer;
while(I==5) {
[Code] ......
There's probably some other better way to do it... Obviously but for now I see it as putting current time in X.
start while
take in time constantly until I is 5
constantly asking is time>X(preset time 5 seconds ahead)
if it is
display message and add one to I
Why doesn't this display my message after 5 seconds?
make a time-in time-out fuction which extracts the no. of hours and minutes from a string entered by the user.
#include <iostream>
#include <fstream>
#include <string>
[Code].....
when we would use add items at design time and when we would add them at run time
does it have anything to do with the page load method? if so, can i type this in source code instead?
why nGrade comes out as 0 every time?
Its as if im not inputting the values into the dynamic arrays in int main.
#include <iostream>
using namespace std;
void Calc(int a_anScores[], int a_anPerc[], int a_nTotal){
for( int iii = 0; iii < a_nTotal; ++iii){
a_anScores[iii] = (a_anScores[iii] * (a_anPerc[iii]/100));
}
int nGrade=0;
[Code]...
I have created this code with the classes for time and message. Basically the point of this code is to give the information of the sender, recipient, time, and message and im having issues with the time part.
#include <iostream>
#include <string>
#include <ctime>
[Code].....
so when you run this you can see i left a spot for the time but I just cant figure out how to figure out the Time part of this.
I am trying to make this while loop cut out / self break after 3 seconds. It is part of a simple game I am creating that gives the users 3 seconds to react otherwise it moves on to the next part.
while(1) {
key=getch();
if(key=='a'||key=='k'||key=='g') {
break;
}
}
All I need is it to end after 3 seconds, the rest of the code is working fine.
This sort of thing:
long startTime = System.currentTimeMillis(); //fetch starting time
while(false||(System.currentTimeMillis()-startTime)<10000)
If it IS for C, then I implemented it wrong or something.
I want to convert time from est to utc. Is there any function for this.
View 3 Replies View RelatedI just spent 3 hours writing and debugging 37 lines of code. Is this normal or am I "below average" in coding abilities. I come from a C background and decided to write C++ code that I finally got right as shown below for the specific example:
Code: #include <iostream>
#include <fstream>
#include <string>
#define SPACE_SEARCH 10
using namespace std;
[code].....
I think it was more the learning along the way that consumed atleast 75% of my time for this specific case. But then again, I read that programming always entails learning along the way and so its somehow no excuse for the long time taken in this specific case.
So as a matter of interest, what pace do all of you operate on, on average? i.e. LOC/day, Debugs per day or any other indicator of productivity?
I tried to write a simple program to calculate monthly yield, APR, and principle in various directions. Anyway, here's some code to get the APR from the principle and monthly yield. When I run it though, it spits 0 at me every time! What the problem is; the other functions work just fine and the code line for the APR calculation is just what it ought to be - I see neither a math nor tech problem here.
Here is the offending function:
Code:
void calculateAPR() {
int principle, monthlyYield, apr;
cout<<"
Please input the principle:";
cin>>principle;
cin.ignore();
[code]....
I am looking for simple code that subtract two time interval. I have time t1=5hour 30 minute and other time in 24 hour format. This code i written but it not working as expected. it not printing 5:30 minute subtract
Code:
main() {
intTime1;
intTime2;
int hour=10;
int minute=5;
int second=13;
int h;int m;
doubleNtime;
[Code] ....