I am writing a code to convert from decimal number to binary number without using library method. But using while loop. It seems it is stuck in a infinite loop.
In debugger mode I tried to see what is the value of x. But even when the value of x gets to 0 or 1, while loop does not exit. Is it a bug in octave or even Matlab has this problem (I don't have Matlab or in any position to use it)?
function ans = dec2bin(input)
x = int16(input);
y = [];
while (x!=1) || (x!=0)
y=[mod(x,int16(2)) y];
x=idivide(x,int16(2));
end
y=[mod(x,int16(2)) y];
ans = arrayfun(#(a) mat2str(a) ,y);
end
The condition (x!=1) || (x!=0) will always be true - if x is 1 it's not equal to 0, and vise-versa. You should use an && logical condition, not an ||:
while (x!=1) && (x!=0)
Related
I would like to check the equality of length of two vectors inside a for loop in R. Is it true to use? or any other suggestion?
if(!(length(dc) == length(gc)))
{
stop("the length are not equall")
}
Update: I completely overlooked the complexity added by arr.sort() method. So in Kotlin for array of Int, It compiles to use java.util.DualPivotQuicksort see this which in turn has complexity of O(n^2). see this. Other than that, this is also a valid approach.
I know It can be solved by keeping multiple arrays or using collections (which is what I ended up submitting), I want to know what I missed in the following approach
fun migratoryBirds(arr: Array<Int>): Int {
var maxCount = 0
var maxType = 0
var count = 0
var type = 0
arr.sort()
println(arr.joinToString(" "))
for (value in arr){
if (type != value){
if (count > maxCount){
maxCount = count
maxType = type
}
// new count values
type = value
count = 1
} else {
count++
}
}
return maxType
}
This code passes every scenario except for Test case 2 which has 73966 items for array. On my local machine, that array of 73k+ elements was causing timeout but I did test for array up-to 20k+ randomly generated value 1..5 and every time it succeeded. But I couldn't manage to pass Test case 2 with this approach. So even though I ended up submitting an answer with collection stream approach, I would really like to know what could I be missing in above logic.
I am running array loop only once Complexity should be O(n), So that could not be reason for failing. I am pre-sorting array in ascending order, and I am checking for > not >=, therefore, If two types end up having same count, It will still return the lower of the two types. And this approach is working correctly even for array of 20k+ elements ( I am getting timeout for anything above 25k elements).
The reason it is failing is this line
arr.sort()
Sorting an array takes O(n logn) time. However using something like a hash map this can be solved in O(n) time.
Here is a quick python solution I made to give you the general idea
# Complete the migratoryBirds function below.
def migratoryBirds(arr):
ans = -1
count = -1
dic = {}
for x in arr:
if x in dic:
dic[x] += 1
else:
dic[x] = 1
if dic[x] > count or dic[x] == count and x < ans:
ans = x
count = dic[x]
return ans
in my code I have the following if statement:
if (a.count >= 2) {
t2 = array[b % a.count];
array[0] = t2;
}
I have another if statement that goes like the first. What I want it to do is if a <= 0 then goto a certain line, or skip over certain parts of code. How would I do this? I was thinking something along the lines of
if (a.count <= 0) {
goto line 96
}
This wouldn't work, the syntax is wrong, but how would I do this?
Goto statements are generally considered bad programming and excessive utilization of them can lead to code that is hard to maintain and debug.
That said, if/else/else if provide all the functionality you need.
I recommend putting the code you need to run inside that if statement in a separate method and then calling it from the if statement.
if (a.count <= 0) {
nameOfNewMethod();
}
//somewhere else
- (void) nameOfNewMethod {
//code here
}
Put the lines of code you want to "goto" in a function (or if appropriate, a block) and call the function (or block). If there are lines of code you want to skip, you can always return early out of a function, or use an else block?
There is in fact a goto command in Objective-C. To utilize it, you have to create a label, ex:
marker:
and jump to it like so within the same method:
goto marker;
But you can't declare any variables between those two commands. All the variables have to be created before the jump so that they still exist after.
Here's an example of how to use goto:
int x = 0;
if (a.count <= 0) {
goto marker;
}
x = 5;
marker:; // <-- semi-colon indicates the label is followed by an empty statement, thus allowing for immediate variable declaration
int y = x + 7;
In that case, if a.count <= 0, y == 7, else y == 12.
I want to make a cave explorer game in game maker 8.0.
I've made a block object and an generator But I'm stuck. Here is my code for the generator
var r;
r = random_range(0, 1);
repeat(room_width/16) {
repeat(room_height/16) {
if (r == 1) {
instance_create(x, y, obj_block)
}
y += 16;
}
x += 16;
}
now i always get a blank frame
You need to use irandom(1) so you get an integer. You also should put it inside the loop so it generates a new value each time.
In the second statement, you are generating a random real value and storing it in r. What you actually require is choosing one of the two values. I recommend that you use the function choose(...) for this. Here goes the corrected statement:
r = choose(0,1); //Choose either 0 or 1 and store it in r
Also, move the above statement to the inner loop. (Because you want to decide whether you want to place a block at the said (x,y) location at every spot, right?)
Also, I recommend that you substitute sprite_width and sprite_height instead of using the value 16 directly, so that any changes you make to the sprite will adjust the resulting layout of the blocks accordingly.
Here is the code with corrections:
var r;
repeat(room_width/sprite_width) {
repeat(room_height/sprite_height) {
r = choose(0, 1);
if (r == 1)
instance_create(x, y, obj_block);
y += sprite_height;
}
x += sprite_width;
}
That should work. I hope that helps!
Looks like you are only creating a instance if r==1. Shouldn't you create a instance every time?
Variable assignment r = random_range(0, 1); is outside the loop. Therefore performed only once before starting the loop.
random_range(0, 1) returns a random real number between 0 and 1 (not integer!). But you have if (r == 1) - the probability of getting 1 is a very small.
as example:
repeat(room_width/16) {
repeat(room_height/16) {
if (irandom(1)) {
instance_create(x, y, obj_block)
}
y += 16;
}
x += 16;
}
Here's a possible, maybe even better solution:
length = room_width/16;
height = room_height/16;
for(xx = 0; xx < length; xx+=1)
{
for(yy = 0; yy < height; yy+=1)
{
if choose(0, 1) = 1 {
instance_create(xx*16, yy*16, obj_block); }
}
}
if you want random caves, you should probably delete random sections of those blocks,
not just single ones.
For bonus points, you could use a seed value for the random cave generation. You can also have a pathway random generation that will have a guaranteed path to the finish with random openings and fake paths that generate randomly from that path. Then you can fill in the extra spaces with other random pieces.
But in regards to your code, you must redefine the random number each time you are placing a block, which is why all of them are the same. It should be called inside of the loops, and should be an integer instead of a decimal value.
Problem is on the first line, you need to put r = something in the for cycle
I have this equation
double x = ((newCount/allCount)/.8)*5.0;
newCount is a double with value 0
allCount is a double with value 0
the result of x is -nan(0x8000000000000)
why this happens and how to check this value in objective c to assign default value for it
You are diving by zero. You can check for it using:
isnan(x)
The problem is that the denominator (allCount) is 0; dividing by zero is not allowed and the answer is not a number. The simplest thing you could do is to test for that before doing the division:
if (allCount != 0) {
x = ((newCount/allCount)/.8)*5.0
} else {
x = defaultValue;
}
There are more complicated ways using C's floating point environment and testing for the FE_DIVBYZERO exception, but while that's standard it's rarely used and therefore potentially more difficult for a later reader of the code to comprehend.
allCount is a 0, thus you just divided by 0 (which is impossible if you didn't know..) So before you assign x, just make sure that allCount is not 0 first.
if (allCount != 0)
double x = ((newCount/allCount)/.8)*5.0;