var i:longint; thap:real;
nhi:string;
begin
readln(nhi); thap:=0;
for i:=1 to length(nhi) do
begin
thap:=thap + (ord(nhi[i])-48)* exp(ln(2)*(length(nhi)-i));
end;
write(thap:2:0);
readln
end.

var n,m,i,j,p,q,k,tam:byte;
a:array[1..100,1..100] of integer;
b:array[1..10000] of integer;
f:text;
function tong(x,y:integer):integer;
var i,j:integer;
begin
tong:=0;
for i:=x to x+p-1 do
for j:=y to y+q-1 do
tong:=tong+a[i,j];
exit(tong);
end;
begin
assign(f,'HCN.inp');reset(f);
readln(f,n,m,p,q);
for i:=1 to n do
begin
for j:=1 to m do read(f,a[i,j]);
readln(f);
end;
close(f);
assign(f,'HCN.out');rewrite(f);
k:=0;
for i:=1 to n-q+1 do
begin
for j:=1 to m-p+1 do
begin
inc(k);
b[k]:=tong(i,j);
end;
end;
for i:=1 to k-1 do
for j:=k downto i+1 do
if b[j]>b[j-1] then
begin
tam:=b[j];
b[j]:=b[j-1];
b[j-1]:=tam;
end;
writeln(f,b[1]+b[2]);
close(f);
readln;
end.

theo hình vẽ, ra ta thấy \(\overrightarrow{B1}v\text{à}\overrightarrow{B2}\) cùng phương, cùng chiều:

=> \(B_M=B1+B2=2\pi.10^{-7}\frac{\left(I1+I2\right)}{r}=7,5\pi.10^{-6}\left(T\right)\)

var f:text;

s:string;

i,dem,max,dau,cuoi:byte;

begin

assign(f,'xau1.txt'); reset(f);

readln(f,s);

close(f);

assign(f,'xau2.txt'); rewrite(f);

dem:=1; max:=1; dau:=1; cuoi:=1;

for i:=1 to length(s)-1 do

begin

if s[i]=s[i+1] then inc(dem) else dem:=1;

if dem>max then

begin

max:=dem;

cuoi:=i+2;

dau:=cuoi-dem;

end;

end;

write(f,dau,':',cuoi);

close(f);

readln;

end.

var n,i,dem:longint;

function cp(so:longint):boolean;

begin

if sqr(trunc(sqrt(so)))=so then exit(true)

else exit(false);

end;

function nt(so:longint):boolean;

var k:longint;

begin

if (so=2) or (so=3) then exit(true);

if (so=1) or (so mod 2=0) or (so mod 3=0) then exit(false);

k:=5;

repeat

if (so mod k =0) or (so mod (k+2)=0) then break;

inc(k,6);

until k>trunc(sqrt(so));

exit(k>trunc(sqrt(so)));

end;

begin

write('nhap n:');readln(n);

dem:=0;

for i:=1 to n do

begin

if (cp(i)) and (nt(trunc(sqrt(i)))) then

begin writeln(i); inc(dem); end;

end;

write(dem);

readln;

end.

code này chạy khoảng 9s nhé! còn cách tối ưu hơn mong mọi người chỉ bảo!

var n,x,dem:byte;

f:text;

function kt(so:byte):boolean;

var k:byte;

begin

if (so=2) or (so=3) then exit(true);

if (so=1) or (so mod 2=0) or (so mod 3=0) then exit(false);

k:=5;

repeat

if (so mod k =0) or (so mod (k+2)=0) then break;

inc(k,6);

until k>trunc(sqrt(so));

exit(k>trunc(sqrt(so)));

end;

begin

assign(f,'NT.inp');reset(f);

readln(f,n);

close(f);

assign(f,'NT.out');rewrite(f);

dem:=0;

for x:=1 to n div 2 do

if (kt(x)) and (kt(n-x)) then inc(dem);

writeln(f,dem);

close(f);

readln

end.

chúc bạn học tốt!

Bài 1

Program bai1;

Uses crt;

Var m,n,i,s:longint;

Begin

Clrscr;

Write ('nhap m:'); readln (m);

Write ('nhap n:'); readln (n);

While n <m do

Begin

Write ('nhap lai n:');

Readln (n);

End;

S:=0;

For i:=m to n do

If (i mod 3=0) or (i mod 5=0) then s:=s+i;

Write (s);

Readln;

End.