Is there any function that returns the maximum number from a subarray of a longint array?
For example:
I have the array: [2,3,6,2,9,4,2,4]
I want the maximum value of the first 5 elements [2,3,6,2,9] of the array (9)
Which is the best solution?
You don't need to create another array.
The 1st solution that would come up is to loop inside your array, taking the first value as 'tempMaxValue', and then fetching your array comparing each value to the 'tempMaxValue'.
If the value is greater than 'tempMaxValue', update 'tempMaxValue' with that particular value and then jump to the next value in the array, otherwise just jump to the next value.
With this solution, you can manage the number of items you want to search into (here you wanted the greatest number within the 5 first elements, so your loop will go from 0 to 4)
Edit : (as #TLama said)
More concretly this is the easy solution: write a function which takes an array, the lowest and the highest indexes as parameter.
program Project1;
uses sysutils;
type TIntegerArray = array of Integer;
function maxInRange(const anArr: TIntegerArray; boundLow, boundHi: Integer): Integer;
var
i: Integer;
begin
result := anArr[boundLow];
for i := boundLow + 1 to boundHi do
if anArr[i] > result then
result := anArr[i];
end;
const
arr: array[0..7] of Integer = (2,3,6,2,9,4,2,4);
begin
writeln(intToStr(maxInRange(arr,0,4)));
readln;
end.
Related
I just started programming and we were given the assignment in the title. I have no idea how to get those numbers in a summable form, so I thought that i will at least write them out, but for some reason i can't see, it doesn't work. Any advice?
var
a,i: integer;
del: array [1..32767] of boolean;
begin
i:=1;
readln(a);
for i:=1 to 32767 do del[i]:=false;
while i<>a do
begin
for i:=1 to 32767 do
begin
if (a MOD i =0) then del[i]:=true;
end
end;
if del[i] then writeln(i,' je delitelem ',a);
end.
Please consider that I am a total newb, thanks!
You're on the right path, but you don't actually even need to store the divisors - just output each one as it is found ( mod = 0 ) and add its value to an accumulator variable.
And then you also don't need the while. Instead, change your for loop to only go up to a instead of 32767.
I am working on my school project and I am (almost) furious about this issue. My solution's validity is 95 %, but I have 1 input wrong – I don't know the input, but I know, that the input failed because of the error code 200, which is divison by 0.
My project is this:
„The digit sum of an integer is defined to be the sum of the digits in the integer's written form. Usually we calculate the digit sum using a number's decimal (base 10) representation, but in this exercise we will compute it in a given base. Write a function that computes a natural number's digit sum when the number is written in a given base. Using this function, write a program that reads two natural numbers (each on its own line, and both in decimal representation): a base B and a number N. The output should be N's digit sum in base B (written in decimal representation).“
I have tried to fix the problem by adding 2 conditions, but it did nothing, mistake still exists.
I am using a formula, which can be found here https://en.wikipedia.org/wiki/Digit_sum .
Here is the code itself, it is not long.
program CifernySoucetZobecneny;
var
Soustava, Cislo, i: longint;
HorniMez: longint;
Soucet: real;
function Mocnina(Zaklad: longint; Exponent: longint): longint;
var
i, Pomoc: longint;
begin
Pomoc := 1;
for i := 1 to Exponent do
begin
Pomoc := Pomoc * Zaklad;
end;
Mocnina := Pomoc;
end;
begin
readLn(Soustava);
readLn(Cislo);
if (Soustava = 0) then
begin
writeLn('0');
exit;
end;
if (Soustava = 1) then
begin
writeLn(Cislo);
exit;
end;
HorniMez := Trunc(Ln(Cislo)/Ln(Soustava));
Soucet := 0;
for i := 0 to HorniMez do
begin
Soucet := Soucet + ((1/Mocnina(Soustava, (i)))*((Cislo mod Mocnina(Soustava, (i+1))) - (Cislo mod Mocnina(Soustava, i))));
end;
writeLn(Soucet:0:0);
end.
I would be grateful if someone could look at the code and told me, where am I dividing by 0, because I tried many inputs, spend many hours on this and did not come with the correct solution. Thank you all.
PS: I am Czech, so the names of the variables and functions are not in English, sorry for that, but I hope, that it will not be a problem.
When Cislo = 0, a following calculation of Ln(Cislo) gives the runtime error 200. That is because Ln(0) is undefined (outside the allowed range of Ln()).
I want to create a loop from i := 1 to n which takes a random number from the procedure and assigns its value to the variables named x1,x2,x3,x4...xn
So it could look like this:
for i:=1 to 100 do begin
GenerateRandomNumber(x); // this procedure gives the updated value of x
xi := x;
end
I want to solve it by creating an array[1..n] of string and then assign this random number to the ith element of the array. But to be honest, I don't like this solution. Is there any faster way? I was thinking about concatenating a string with a number, or converting "x" (the string) to a number and then somehow merging it with the consecutive values of i. What do you think?
I've been trying lately to write a program(a text based game) but I only know some commands and don't understand every command very well.
What I am trying to do is a hit chance. Lets say that I want the program to have
90% chance of choosing number 1 (which means hit) and
10% to choose number 0 (which means miss).
I saw the same question Here but I don't understand the commands because I've never used them (I'm talking about set.seed and sample). Could someone explain to me how do they work? Is there another way (easier to understand? I don't mind if it consumes more resource)
program Project1;
{$ASSERTIONS ON}
function getProb(aProbability: Integer): boolean;
begin
result := aProbability > (100 - random(100));
end;
procedure miss;
begin
writeln('miss');
end;
procedure hit;
begin
writeln('hit');
end;
var
i, success, probability, errorMarge: Integer;
const
combat: array[boolean] of procedure = (#miss, #hit);
begin
// show that getProb() is reliable
errorMarge := 4;
success := 0;
probability := 80;
for i in [0..99] do
Inc(success, Byte(getProb(probability)));
assert(success >= probability - errorMarge);
success := 0;
probability := 50;
for i in [0..99] do
Inc(success, Byte(getProb(probability)));
assert(success >= probability - errorMarge);
// example usage
combat[getProb(20)];
combat[getProb(80)];
combat[getProb(90)];
readln;
end.
Not knowing what "commands" you know, this is hard to answer w/o generalizing.
If you only need to choose between two values, then generate a random value in whatever range you know how to, and compute the dividing line based on your probability. So, for your example, if you can generate a value between 0 and 1, if it is <= 0.9, hit.
This can be extended to multiple values by adding the successive probabilities. So if you have 4 values to choose between, each with 25% probability, get you random value between 0 and 1: if it is less than 0.25, choose 0 else if less than 0.5, choose 1 else if less than 0.75 choose 2 otherwise choose 3.
I want to get a random number in pascal from between a range. Basically something like this:
r = random(100,200);
The above code would then have a random number between 100 and 200.
Any ideas?
The built in pascal function only lets you get a number from between 0-your range, while i need to specify the minimum number to return
Just get a random number with the correct range (ie 100 to 200 would be range 100) then add the starting value to it
So: random(100) + 100 for your example
As already pointed out, you should use
myrandomnumber := random(span) + basenumber;
However, to get better quality random numbers, you should call
randomize();
once, on start of your application, to initialize the random number generator.
Couldn't you just declare a starting variable and an end variable and pass random those? e.g.
var
varMyRandomNumber, x, y := extended;
begin
x := 100;
y := 200;
varMyRandomNumber := random(x,y);
ShowMessage(IntToStr(varMyRandomNumber));
end;
?
There's a good example here of using a for loop to set starting and end values : http://www.freepascal.org/docs-html/rtl/system/random.html
Use RandomRange or RandomFrom:
function RandomRange(const aFrom: Integer; const aTo: Integer): Integer;
RandomFrom returns a random element from the array AValues. The return value has the same type as the type of the array elements.
first of all, i recommend you to use Randomize at the beginning of the program (it changes the algorithm of selecting the number).
To get a random number between some two numbers you need this:
Result:=Min+random(10000)mod max + 1;
I don't remember the maximum value for random, so you can change it (it don't changes anything).
By using 'mod' you get module from division Random and max. +1 is needed, because you never get the number that = max, only the number that =max-1, so you need to write +1.
Good luck!
You can make it like
Int:=Random(100);
it give's 100 random numbers.
then when you display it or use it just add 101 to that integer so its between 100 and 200