A while loop is a type of loop that runs as long as a logical condition is True. When the logical condition becomes False, the loop stops running. The general form of a while loop in Python is below:
while <logical_condition>: <code>
The keyword while must be included, as well as a <logical_condition> which can be evaluated as True or False. The <code> after the while statement must be indented. Each line of code runs in the while loop needs to be indented the same number of spaces. (Many code editors, including Jupyter notebooks, auto-indent after a whilestatement) If you add indentation manually, four space spaces is the Python standard.
An example of a while loop is below:
In [1]:
i = 0 while i<4: print(i) i = i+1
The first line i=0 creates the variable i and assigns it the value 0. The next line declares the logical condition needed to keep the loop running. The statement i<4 is True or False depending on the variable i. Since i=0, the statement i<4 is Trueand the while loop starts to run. The code inside while the loop prints the value of i then increases iby 1. When i=4, the statement i<4 is False and the while loop ends.
n,k,i:integer;
begin
for n:=1 to 2 do
begin
writeln('Введите строку ',n,':');
readln(s);
k:=0;
for i:=1 to length(s) do
begin
case s[i] of
'[': k:=k+1;
']': k:=k-1;
end;
end;
if k=0
then writeln('В строке ',s,' количество [ и ] одинаково')
else writeln('В строке ',s,' количество [ и ] не одинаково');
end;
end.
Пример:
Введите строку 1:
c:=a[imax,j]; a[imax,j]:=a[imin,j]; a[imin,j]:=c
В строке c:=a[imax,j]; a[imax,j]:=a[imin,j]; a[imin,j]:=c количество [ и ] одинаково
Введите строку 2:
Просто [ пример ]] со [[ скобками
В строке Просто [ пример ]] со [[ скобками количество [ и ] не одинаково