Câu 21: 

#include <bits/stdc++.h>

using namespace std;

long long a[1000],n,i,nn;

int main()

{

cin>>n;

for (i=1; i<=n; i++) cin>>a[i];

nn=LLONG_MAX;

for (i=1; i<=n; i++) nn=min(nn,a[i]);

for (i=n; i>=1; i--)

if (nn==a[i]) 

{

cout<<i;

break;

}

return 0;

}

Câu 21 :

uses crt;

var A : array [1 .. 100] of integer;

i, n, m, j : integer;

begin

clrscr;

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

write('Nhap day gom ', n ,' so : ');

for i := 1 to n do read(A[i]);

m := A[n]; j := n;

for i := n downto 2 do

if A[i] < m then begin m := A[i]; j := i; end;

write('Phan tu nho nhat cuoi cung A[',j,'] = ', m);

readln

end.

Câu 22 :

uses crt;

var S : string; k : byte;

begin

clrscr;

write('Nhap xau S : '); readln(S);

while pos('Doan hung', S) <> 0 do

    begin

        k := pos('Doan hung', S);

        delete(S, k, 9);

        insert('Ha hoa', S, k);

        end;

write('Xau moi : ', S);

readln

end.