MᏫᎻᎯᎷᎷᎬᎠ
It's all because a leading software companies
They determine what is done and what is not for their self benefits
Anonymous
Thanks
MᏫᎻᎯᎷᎷᎬᎠ
Libraries can be developed to ease and speed up the development time
Anonymous
Henry
Just google stuff you want to learn (e.g. you have an error or need to learn something), analyze what you get and solve your problems on your own.
Henry
That is what are software engineers paid for.
Anonymous
Yes
PO
guys need your help
PO
with these 2 loops I can rotate 180° my matrix
for(unsigned int i = 0; i < raw; i++){
for(unsigned int j = 0; j < column; j++){
rotate_matrix[i][j] = old_matrix[raw - 1 - i][column - 1 -j];
}
}
PO
how can I do the same If I want write my loop like that :
for(unsigned int i = raw; i >=0 ;i--){
for(unsigned int j = column; j >= 0 ;j--){
"I don't know what should I put here!😭 "
}
}
PO
I have tried that but it doesn't work (" rotate_matrix[raw-i-1][column-j-1] = old_matrix[i-1][j-1]; ")
Anonymous
how can I do the same If I want write my loop like that :
for(unsigned int i = raw; i >=0 ;i--){
for(unsigned int j = column; j >= 0 ;j--){
"I don't know what should I put here!😭 "
}
}
write the loop as
for (auto i = row; i-- != 0;) {
for (auto j = column; j-- != 0;) {
PO
write the loop as
for (auto i = row; i-- != 0;) {
for (auto j = column; j-- != 0;) {
what is that "auto"?
Dexter
what is that "auto"?
It will automatically inherit the type of datatype used from the initializer
PO
It will automatically inherit the type of datatype used from the initializer
there isn't an other way?
PO
write the loop as
for (auto i = row; i-- != 0;) {
for (auto j = column; j-- != 0;) {
There is an other way to do that?
Anonymous
There is an other way to do that?
for (auto i = row; i != 0 ; --i) {
for (auto j = column; j != 0 ; --j) {
and then using [i - 1] and [j - 1] wherever needed
PO
Anonymous
ok thank you
also, in C++ you should use != in tests unless you absolutely need to use something else. this keeps consistency with comparisons when you use non-random access iterators
PO
PO
PO
auto was for C++. in C auto currently means automatic variable.
oh shit, so I can't use what you told me
Anonymous
oh shit, so I can't use what you told me
just use unsigned int in place of auto like you were already doing
PO
But I don't know what I have to put in corps of my loop
Anonymous
But I don't know what I have to put in corps of my loop
what's the problem with
rotate_matrix[i][j] = old_matrix[row - 1 - i][column - 1 - j];?
PO
what's the problem with
rotate_matrix[i][j] = old_matrix[row - 1 - i][column - 1 - j];?
it doesn't work and I get segmentation fault
PO
wdym?
I've to find out what should I put inside my loop's corps when I write my loop like that:
for(unsigned int i = raw; i >=0 ;i--){
for(unsigned int j = column; j >= 0 ;j--)
Anonymous
I've to find out what should I put inside my loop's corps when I write my loop like that:
for(unsigned int i = raw; i >=0 ;i--){
for(unsigned int j = column; j >= 0 ;j--)
change it to
for (unsigned int i = row; i >= 0; i--) {
if (i == row) { continue; }
for (unsigned int j = column; j >= 0; j--) {
if (j == column) { continue; }
PO
PO
Is it a function in stdio.h?
Anonymous
What does it mean continue?
in a for loop continue means run the loop expression, then test the loop condition
Anonymous
What does it mean continue?
but this code is terrible. if row is equal to 0, this will be an infinite loop
Anonymous
so you have to do
PO
but this code is terrible. if row is equal to 0, this will be an infinite loop
So It doesn't work
Anonymous
for (unsigned int i = row; i >= 0; i--) {
if (row == 0) { break; }
if (i == row) { continue; }
for (unsigned int j = column; j >= 0; j--) {
if (column == 0) { break; }
if (j == column) { continue; }
Anonymous
which is even more terrible. while it fixes the infinite loop, the code is getting messier and messier
Anonymous
soooooooo
Anonymous
I've to find out what should I put inside my loop's corps when I write my loop like that:
for(unsigned int i = raw; i >=0 ;i--){
for(unsigned int j = column; j >= 0 ;j--)
do not write a loop like this in the first place
PO
which is even more terrible. while it fixes the infinite loop, the code is getting messier and messier
Cool my firend, I won't even try it don't worry
PO
do not write a loop like this in the first place
I have to find on other way because my teacher is asking
PO
Dexter
with these 2 loops I can rotate 180° my matrix
for(unsigned int i = 0; i < raw; i++){
for(unsigned int j = 0; j < column; j++){
rotate_matrix[i][j] = old_matrix[raw - 1 - i][column - 1 -j];
}
}
if u are talking about this code then replace auto with unsigned int
Dexter
👍
PO
👍
for(unsigned int i = raw; i >=0 ;i--){
for(unsigned int j = column; j >= 0 ;j--){
rotate_matrix[i-1][j-1] = old_matrix[i][j];
}
}
PO
I get segmentation fault
Anonymous
write the loop as
for (auto i = row; i-- != 0;) {
for (auto j = column; j-- != 0;) {
1
for (unsigned int i = row; i-- > 0;) {
for (unsigned int j = column; j-- > 0;) {
rotate_matrix[i][j] = old_matrix[row - 1 - i][column - 1 - j];
}
}
Anonymous
for (auto i = row; i != 0 ; --i) {
for (auto j = column; j != 0 ; --j) {
and then using [i - 1] and [j - 1] wherever needed
2
for (unsigned int i = row; i > 0; --i) {
for (unsigned int j = column; j > 0; --j) {
rotate_matrix[i - 1][j - 1] = old_matrix[row - i][column - j];
}
}
PO
I'm trying
PO
PO
1
for (unsigned int i = row; i-- > 0;) {
for (unsigned int j = column; j-- > 0;) {
rotate_matrix[i][j] = old_matrix[row - 1 - i][column - 1 - j];
}
}
I don't get seg fault, but it doesn't work
PO
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
1 0 0 0 1 0
0 1 1 1 0 0
0 0 0 0 0 0
0 0 0 0 0 0
PO
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
0 0 0 0 1 0
1 0 0 0 1 0
0 1 1 1 0 0
0 0 0 0 0 0
0 0 0 0 0 0
I have to rotate 180° this matrice
PO
1
for (unsigned int i = row; i-- > 0;) {
for (unsigned int j = column; j-- > 0;) {
rotate_matrix[i][j] = old_matrix[row - 1 - i][column - 1 - j];
}
}
why did you write i-->0 and how did you understand that?
PO
for (unsigned int i = raw; i > 0; i--) {
for (unsigned int j = column; j > 0; j--) {
rotate_matrix[i - 1][j - 1] = old_matrix[raw - i][column - j];
}
}
PO
for (unsigned int i = raw; i > 0; i--) {
for (unsigned int j = column; j > 0; j--) {
rotate_matrix[i - 1][j - 1] = old_matrix[raw - i][column - j];
}
}
It doesn't rotate the matrix but I don't get segmentation fault
Anonymous
I get segmentation fault
that's likely a fault in your code and not in the 4 lines i wrote
PO
same with this
the same code works with :
for(unsigned int i = 0; i < raw; i++){
for(unsigned int j = 0; j < column; j++){
rotate_matrix[i][j] = old_matrix[raw - 1 - i][column - 1 -j];
}
}
Anonymous
Anonymous