Program HOC24;

var i,n: integer;

S: real;

begin

write('Nhap N: '); readln(n);

s:=0;

for i:=1 to N do s:=s+1/i;

write('S= ',s:5:2);

readln

end.

câu 1:

uses crt;

var p,i:integer;

begin

clrscr;

p:=1;i:=1;while i<=5 do

begin

p:=p*i;i:=i+1;

end;

write(p);

readln;

end. 

bai 2:

uses crt;var p,i:integer;begin    clrscr;    p:=1; i:=0;    while i <=10 do    begin

i:=i+1;        if (i mod 2<>0) then p:=p*i;    end;    write(p);    readln;end. bai 3:

uses crt;var n,i,p:integer;begin     clrscr;     write('nhap n: ');     readln(n);     i:=1;     p:=1;     while i<=n do     begin       if i mod 2=0 then p:=p*i;       i:=i+1;     end;     write(p);     readln;end.     

*Cách khác: Dùng for

Câu 1: 

uses crt;

var p,i:longint;

begin

p:=1;

for i:=1 to 4 do 

  p:=p*i;

writeln(p);

readln;

end.

Câu 2: 

uses crt;

var i,s:longint;

begin

clrscr;

s:=1;

for i:=1 to 10 do

  if i mod 2=1 then s:=s*i;

writeln(s);

readln;

end.

Câu 3: 

uses crt;

var n,i,s:longint;

begin

clrscr;

write('Nhap n='); readln(n);

s:=0;

for i:=1 to n do 

  if i mod 2=0 then s:=s+i;

writeln(s);

readln;

end.

Số chẵn:

Var i,n,S: longint;

Begin

Readln(n);

For i:=1 to n do 

If i mod 2 = 0 then S:=S+i

Write(S);

Readln

End.

Số lẻ:

Var i,n,S: longint;

Begin

Readln(n);

For i:=1 to n do 

If i mod 2 = 1 then S:=S+i

Write(S);

Readln

End.

#include <bits/stdc++.h>

using namespace std;

long long x,n,i,t1,t2;

int main()

{

cin>>n;

t1=0;

t2=0;

for (i=1; i<=n; i++)

{

cin>>x;

if (x%2==0) t1+=x;

else t2+=x;

}

cout<<t1<<" "<<t2;

return 0;

}

program day_du_cau_lenh;

uses crt;

var i,n:integer;

a:array[1..100]of intrger;

begin

clrscr;

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

i:=1;

while i<=n do

begin

write('nhap a[',i,']:');readln(a[i]);

i:=i+1;

end;

for i:=1 to n do

if a[i]>=0 then write(a[i]) else write('');

readln;

end.

program tong_100_so_tu_nhien;

uses crt;

var i, S: integer;

begin

      S := 0;

      for i := 1 to 100 do

            S := S + i;

      writeln('Tong cua 100 so tu nhien dau tien la ', S);

      readln;

end.

Var i,s:integer;

Begin

i:=1;

s:=0;

While i<=100 do

Begin

s:=s+i;

i:=i+1;

End;

Write('Tong la ',s);

Readln;

End.

Tổng n số tự nhiên đầu tiên:

Var i,n,s:integer;

Begin

Write('n = ');

for i:=1 to n do

s:=s+i;

Write('Tong la ',s);

Readln

End.

Tích các số từ 5 đến 30

Var i,p:longint;

Begin

p:=1;

For i:=5 to 30 do

P:=p*i;

Write('Tich la ',p);

Readln

End.

Chu vi, diện tích hình chữ nhật:

var a,b,p,s:real;

begin

write('Chieu dai hcn = ');readln(a);

write('Chieu rong hcn = ');readln(b);

p:=(a+b)*2;

s:=a*b;

writeln('Chu vi hcn la ',p:10:2);

write('Dien tich hcn la ',s:10:2);

readln

end.

------------------------------------------------------------

Chu vi, diện tích hình tròn:

var r,c,s:real;

begin

write('Ban kinh = ');readln(r);

c:=2*3.14*r;

s:=3.14*r*r;

writeln('Chu vi hinh tron la ',c:10:2);

write('Dien tich hinh tron la ',s:10:2);

readln

end.

---------------------------------------------------

Chu vi, diện tích hình thang:

var dl,dn,cb1,cb2,h,p,s:real;

begin

write('Day lon = ');readln(dl);

write('Day be = ');readln(db);

write('Chieu cao = ');readln(h);

write('Canh ben thu nhat = ');readln(cb1);

write('Canh ben thu hai = ');readln(cb2);

p:=dl+db+cb1+cb2;

s:=(dl+db)*h/2;

writeln('Chu vi hinh thang la ',p:10:2);

write('Dien tich hinh thang la ',s:10:2);

readln

end.