I'm trying to write a program to check if a number between 1 and 9999999 is a number whose digits either stay the same or increases from left to right(The variable and function names are in Vietnamese)
#include<stdio.h>
int daykhonggiam(int n)
{
while (n>=10)
{
int donvi=n%10;
n=n/10;
if(donvi<n%10)
{
return 0;
}
}
return 1;
}
int main(void)
{
for(int i=1;i<=9999999;i++)
{
if(daykhonggiam(i)==1)
printf("%d\n",i);
}
}
The problem is, when i compile and run the code ,only some of the results were shown( the results from 5555999 to 9999999 ). when i hit f9 i can the the results run from 1 but the final screen only shows from 5555999 to 9999999. I tried an online compiler and all the results were shown.
So i guessing my dev c++ 5.11 is the problem here. Is there any chance any of you know why that's the case ?
It looks like printf just fills console buffer completely and old lines get removed. Try writing results to file or increase console buffer capacity somehow.
Open your terminal, click the top left corner, go to properties, and increase your buffer size. Save, and test. Repeat if needed.
That being said, I concur with previous comments that you should just use an output file.
Edit: After some testing, I could only get a max number of 9,000 lines to display concurrently. I'd pursue using an output file in your case.
Related
The famous text scrolling effect has been used in many games, and I mean many console-based-RPG games.
I'm somewhat trying to make my own as a novice project to sharpen my C++ skills, however, I got stuck somewhere.
You see, while a stream of text is scrolling, the player eventually gets bored and wants to skip those texts.
What happens is, that when the player presses a certain key, the text stops scrolling(and by scrolling I mean spitting out characters of a string with increasing index i with a slight delay) and it spits out everything at once.
This is quite the effect which I am trying to replicate.
This is the I currently use (without the skip-through effect):
for(int i = 0; i<text.length();i++)
{
std::cout << text[i];
Sleep(200);//WINAPI function for timeout. DWORD Milliseconds as argument
}
And the one that I want:
for(int i = 0; i<text.length();i++)
{
std::cout << text[i];
if(GetAsyncState(VK_RETURN)
{
continue;
}
else{
Sleep(200);//WINAPI function for timeout. DWORD Milliseconds as argument
}
}
This is very novice code, so please don't criticize me.
So I end this shtick with my question:
How to stop text from streaming with a delay, and to make it output it all at once.
Have a nice day!
Can anyone explain me the difference in the execution of both of the codes?
1)
#include <iostream>
using namespace std;
int main() {
// your code goes here
string code;
getline(cin,code);
for(int i=0;i<code.length();i++){
if(code[i]=='.'){
code.replace(i,1,"[.]");
}
}
cout<<code;
return 0;
}
The output screen of the above program code shows "time limit exceeded".
Time limit exceeded #stdin #stdout 5s 5220KB
#include <iostream>
using namespace std;
int main() {
// your code goes here
string code;
getline(cin,code);
for(int i=0;i<code.length();i++){
if(code[i]=='.'){
code.replace(i,1,"[.]");
i++;
}
}
cout<<code;
return 0;
}
whereas no.2 code shows the output as desired.
1[.]1[.]1[.]1
Can anyone explain how the execution took in both of the cases that one of the output shows "TLE"(the iteration count has to be declared in the for loop itself) and whereas the other one displays the output?
In this loop:
for(int i=0;i<code.length();i++){
if(code[i]=='.'){
code.replace(i,1,"[.]");
}
}
when you do a replacement of [.], in the next iteration of the loop i is now the index of the . that you just inserted. That . will be replaced again, and so on, infinitely many times, leading to a "time limit exceeded".
In the 2nd version, when a replacement is done, i is correctly being moved to point to the ] instead. You could move it one step further as well, since you know there is no . at that position either.
We can do this and see what happens, for example with this input:
code = "google.com"
After a while, i will be equal to 6, and then it happens:
i code
6 google[.]com (and now there's a dot on place 7)
7 google[[.]]com (and now there's a dot on place 8)
8 google[[[.]]]com (and now there's a dot on place 9)
... ...
And there is no way to stop this.
As the replacement makes the place of the dot shift one to the right, it might be a good idea to have a for-loop in the other sense:
for(int i=code.length()-1;i>=0;i--)
so I'm trying to write a guess the number game in C++.The computer is Supposed to take a random number with 4 digits then the player should enter a number too.Rules are:
if the computer chooses:1234
And the player enters:1356
1 must be displayed in green,3 must in yellow since it's in the wrong place and 5&6 in red.the game goes on till the player gets the right answer.
#include<iostream>
#include <windows.h>
#include <stdlib.h>
#include <time.h>
#include<unistd.h>
using namespace std;
int main()
{
int b;
HANDLE handle=GetStdHandle(STD_OUTPUT_HANDLE);
cout<<"System is now generating a number...."<<"\n";
int *Number = new int[4];
srand (time(NULL));
for(int counter=0;counter<4;)
{
Number[counter]=(rand()%9)+1;
if(Number[counter]!=Number[counter-1]&Number[counter]!=Number[counter-2]
2]&Number[counter]!=Number[counter-3])
{
counter ++;
}
else
{
counter--;
}
}
cout<<Number[0]<<Number[1]<<Number[2]<<Number[3]<<"\n";
int *Guess=new int[4];
cout<<"please enter 4 digits for your number"<<"\n";
for(int counterG=0;counterG<4;counterG++) //line 34
{
cin>>Guess[counterG];
for(int counter;counter<4&counter>0;)
{
if((counter=counterG)&(Guess[counterG]=Number[counter])) //line 40
{
b=Guess[counterG];
SetConsoleTextAttribute(handle,10);
cout<<b<<"\n";
}
if((counter=counterG)&(Guess[counterG]==Number[counter- 1]|Guess[counterG]==Number[counter+1]|Guess[counterG]==Number[counter-2]|Guess[counterG]==Number[counter+2]))
{
b=Guess[counterG];
SetConsoleTextAttribute(handle,14);
cout<<b<<"\n";
}
else
{
b=Guess[counterG];
SetConsoleTextAttribute(handle,12);
cout<<b<<"\n";
}
}
}
now the program is fine until line 34 but nothing happens after that!
It just gets the player digits
I'd be glad if you could tell me what I've done wrong
Not a complete answer, but it's too long for a comment:
if(Number[counter]!=Number[counter-1]&Number[counter]!=Number[counter-2]
2]&Number[counter]!=Number[counter-3])
This line alone contains a lot of errors:
To have the logical AND operator you need &&, not &.
You have typed an extra 2] at the beginning of the second line. I hope it's just a typo that you introduced when writing the question.
The first time you run this, counter is 0. What happens when you try to access Number[counter-3]? It's an out of bounds access, which leads to Undefined Behaviour, which can lead to anything.
And there are probably many more.
What to do now:
Work on your code indentation. It's really bad.
Start from a much simpler program, and verify that it works. Then, add one small step, verify it, and don't move on until you are happy with the result
Turn on your compiler warnings. Warnings are your friends, not a boring annoyance
Learn how to use a debugger. You won't go very far without debugging.
1- replace & with &&(AND operator)
2- take input in a simple integer variable and then validate the number by performing first check of number greater than 0 and less than 9999.
3- then seperate digits from this variable and then assign those digits to aaray indexes respectvely.
I've written a simple code to practice some stuff, but it's not running as it's supposed to.
I'm programming on my iPhone just for fun and l'm using an app called c/c++ offline compiler which seems to work really well.
Anyway, I wrote a program to display numbers, and if the number is less than 5 digits, in each empty space display a star. Then next to that, display the memory address.
There are two questions I have. First, why are the stars not displaying when I run this. Second, each time run it, the memory addresses are different. Is this because of the compiler, or because of how the iPhone's memory works?
Source Code:
//c plus plus program 1
#include <iostream>
using namespace std;
int main (void){
for(int i=0; i<150;i+=30){
cout.width(5);
cout.fill('*');
cout<<i<< "="<<&i <<endl;
}
return 0;
}
It is normal that address of i is changing each time you run your program. As I know it is because of how system works with memory. Why did you think it will place your program in the same part every time? :-)
I tried you code in http://cpp.sh only and stars were shown:
****0=0xffcde9dc
***30=0xffcde9dc
***60=0xffcde9dc
***90=0xffcde9dc
**120=0xffcde9dc
Note, that all after second << was not took into consideration when output width was determined. So first of all to investigate the problem I would try something like
int main (void) {
cout.width(5);
cout.fill('*');
cout << 1 << endl;
cout << 2 << endl;
}
to understand if it compiler problem or not.
I am trying to implement quickHull algorithm (for convex hull) parallely in CUDA. It works correctly for input_size <= 1 million. When I try 10 million points, the program crashes. My graphic card size is 1982 MB and all my data structures in the algorithm collectively require not more than 600 MB for this input size, which is less than 50 % of the available space.
By commenting out lines of my kernels, I found out that the crash occurs when I try to access array element and the index of the element I am trying to access is not out of bounds (double checked). The following is the kernel code where it crashes.
for(unsigned int i = old_setIndex; i < old_setIndex + old_setS[tid]; i++)
{
int pI = old_set[i];
if(pI <= -1 || pI > pts.size())
{
printf("Thread %d: i = %d, pI = %d\n", tid, i, pI);
continue;
}
p = pts[pI];
double d = distance(A,B,p);
if(d > dist) {
dist = d;
furthestPoint = i;
fpi = pI;
}
}
//fpi = old_set[furthestPoint];
//printf("Thread %d: Furthestpoint = %d\n", tid, furthestPoint);
My code crashes when I uncomment the statements (array access and printf) after the for loop. I am unable to explain the error as furthestPoint is always within bounds of old_set array size. Old_setS stores the size of smaller arrays that each thread can operate on. It crashes even if just try to print the value of furthestPoint (last line) without the array access statement above it.
There's no problem with the above code for input size <= 1 million. Am I overflowing some buffer in the device in case of 10 million?
Please help me in finding the source of the crash.
There is no out of bounds memory access in your code (or at least not one which is causing the symptoms you are seeing).
What is happening is that your kernel is being killed by the display driver because it is taking too much time to execute on your display GPU. All CUDA platform display drivers include a time limit for any operation on the GPU. This exists to prevent the display from freezing for a sufficiently long time that either the OS kernel panics or the user panics and thinks the machine has crashed. On the windows platform you are using, the time limit is about 2 seconds.
What has partly mislead you into thinking the source of the problem is array adressing is the commenting out of code makes the problem disappear. But what really happens there is an artifact of compiler optimization. When you comment out a global memory write, the compiler recognizes that the calculations which lead to the value being stored are unused, and it removes all that code from the assembler code it emits (google "nvcc dead code removal" for more information). That has the effect of making the code run much faster and puts it under the display driver time limit.
For workarounds see this recent stackoverflow question and answer