Anonymous
sorray, O(n)
Anonymous
seem to O(n)
Anonymous
yep, if use it, can be O(n)
Anonymous
bc just for n time
Anonymous
create a linked list is a way, but it will increase the amount of code
Anonymous
Yeah, but I think linked list is optimal for space😂
Anonymous
C is too low-level. I really love and hate
Anonymous
😂STL really a nice mind, iI really admire whoever came up with this
İbn
Anonymous
how to find the the corresponding value?
İbn
#include<iostream>
#include<string>
using namespace std;
int main()
{
int arr1[] = {1, 2, 3};
int hash_table[N] = {0};
if (arr1[i] == 1)
hash_table[0]++
if (arr1[i] == 2)
hash_table[1]++
....
if arr1[i] == 1
hash_table[0]++
...
if hash_table[i] == 2
the i number is wrong
return 0;}
Anonymous
The code I wrote is pseudo code and only has a solution
Anonymous
I just borrowed the code to express my thinking
Anonymous
haha
Anonymous
if u can do cpp, u use the unordered_map is a good way just Mark said
Anonymous
u can look through the records
İbn
Ok..i will try
Anonymous
Don't worry, the sense of achievement u've made is amazing
Anonymous
#include<iostream>
#include<string>
using namespace std;
int main()
{
int arr1[] = {1, 2, 3};
int hash_table[N] = {0};
if (arr1[i] == 1)
hash_table[0]++
if (arr1[i] == 2)
hash_table[1]++
....
if arr1[i] == 1
hash_table[0]++
...
if hash_table[i] == 2
the i number is wrong
return 0;}
/*When you are to assign default value to null, you no longer need to {0}. That's enough {}*/#include<iostream>
#include<string>
using namespace std;
int main()
{
...
int hash_table[N] = {};
...
return 0;}
\Device\NUL
Hello, is it possible to allocate and free heap memory using kernel syscall directly (without libc) ?
Anonymous
haha，just habit to write{0}
Anonymous
This will let me know the meaning of the code more clearly
Pol
Hi !
Pol
I just joined the group.
Danya🔥
The message from @drupol:
I'm looking for some help with a C program that I'm trying to do. Basically I would like to create an implode function where I could print an array of integers with a separator in between elements. I did this, but for some reason, it won't work and I'm unable to debug in CLion: https://gist.github.com/drupol/97467ea7214e4118623c4f6116d332b0 could you give me some clue ?
Pol
Ah nice ! thanks :) I was about to rewrite the message without the link !
Pol
Do you think anyone can help? I'm stuck on this thing and I can't figure out how to fix it.
Danya🔥
Ah nice ! thanks :) I was about to rewrite the message without the link !
> strcat(str, arr[i]);
Are you sure that it is going to work as you implied?
Danya🔥
And I'm going to answer it: no, arr[i] is an int
strcat doesn't accept ints
Danya🔥
I don't think it should even compile
Danya🔥
Anyways, you should use itoa or sprintf
Pol
Wait, trying ! :)
Danya🔥
Also, are you sure that sprintf can accept NULL as the first argument?
Pol
I don't know that, I'm learning C
Pol
I did this: sprintf(str, "%s%s%d", str, separator, arr[i]);
Pol
But I'm absolutely not sure yet.
Pol
I'm a bit discouraged when I see that this kind of stuff is so complex in C
Pol
Got it working !
Pol
for (int i = 0; i < size; i++) {
if (i == size - 1) {
sprintf(str, "%s%d", str, arr[i]);
} else {
sprintf(str, "%s%d%s", str, arr[i], separator);
}
}
Danya🔥
Danya🔥
for (int i = 0; i < size; i++) {
const char* suffix = (i < size-1) ? separator : "";
sprintf(str, "%s%d%s", str, arr[i], suffix);
}
Pol
beautiful, trying.
Pol
Danya🔥
for (int i = 0; i < size; i++) {
const char* suffix = (i < size-1) ? separator : "";
sprintf(str, "%s%d%s", str, arr[i], suffix);
}
Well, also, always rewriting str seems inefficient
Danya🔥
for (int i = 0; i < size; i++) {
const char* suffix = (i < size-1) ? separator : "";
str += sprintf(str, "%d%s", arr[i], suffix);
}
Danya🔥
@drupol try this
Pol
@drupol try this
Doesn't print anything this time. But I agree that rewriting str is inefficient.
Danya🔥
Doesn't print anything this time. But I agree that rewriting str is inefficient.
Well, I'm not able to check it right now. If you could make it working, that'd be awesome
Pol
Well, I'm not able to check it right now. If you could make it working, that'd be awesome
I'm trying :) Thanks !
Pol
ahh ?
Danya🔥
for (int i = 0; i < size; i++) {
const char* suffix = (i < size-1) ? separator : "";
str += sprintf(str, "%d%s", arr[i], suffix);
str--;
}
Danya🔥
So probably we can hack it with - 1
Danya🔥
The code is different
Pol
I could get rid of '\0' ?
Pol
trying
Pol
Same result.
Danya🔥
Weird
Danya🔥
for (int i = 0; i < size; i++) {
const char* suffix = (i < size-1) ? separator : "";
sprintf(str, "%s%d%s", str, arr[i], suffix);
}
Also, the initial example is not correct, @drupol
If a call to sprintf or snprintf causes copying to take place between objects that overlap, the behavior is undefined (e.g. sprintf(buf, "%s text", buf);)
Pol
ok fair enough, going to fix this
Danya🔥
So I just suggest it to rewrite to strcat+itoa or make my last try working
Pol
Ok, checking this out.
Danya🔥
for (int i = 0; i < size; i++) {
const char* suffix = (i < size-1) ? separator : "";
str += snprintf(str, size, "%d%s", arr[i], suffix);
str--; // try with this line and without
}
Danya🔥
This could work
Pol
Nope, only prints 1 single digit, nothing else.
Pol
I added a todo (in french!)
Pol
for (int i = 0; i < size; i++) {
// TODO: Optimizer ce truc pour eviter de devoir re-ecrire str
sprintf(str, "%s%d%s", str, arr[i], (i < size-1) ? separator : "");
}
Pol
I don't have itoa.
Pol
how come?
Pol
Going to use sprintf instead.
Anonymous
Is this the new standard?emm，just {} because the underlying initialization is 0 by default?
Anonymous
I don't have itoa.
itoa is not a standard library function. Some compiler implementations provide it in stdlib.h as an extension