C, pasted on Oct 5:
 ```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 ``` ```#include #include #include #define MAX 100 void nhap (int a[], int &n) { do { printf("\nNhap so phan tu: "); scanf("%d", &n); if(n <= 0 || n > MAX) { printf("\nSo phan tu khong hop le. Xin kiem tra lai !"); } }while(n <= 0 || n > MAX); for(int i = 0; i < n; i++) { printf("\nNhap a[%d]: ", i); scanf("%d", &a[i]); } } void xuat(int a[], int n) { for(int i = 0; i < n; i++) { printf("%4d", a[i]); } } /* 1234 1234 / 10 = 123 -> bỏ đi hàng đơn vị 123 % 10 = 3 -> lấy chữ số hàng chục */ int TimSoHangChuc5(int n) { n = abs(n); n = n / 10; int hangchuc = n % 10; if(hangchuc == 5) { return 1; } return 0; } int TinhTongSoHangChuc5(int a[], int n) { int Tong = 0; for(int i = 0; i < n; i++) { if(TimSoHangChuc5(a[i]) == 1) { Tong += a[i]; } } return Tong; } int main() { int n; int a[MAX]; nhap(a, n); xuat(a, n); int TongChuc5 = TinhTongSoHangChuc5(a, n); printf("\nTong cac phan tu co chu so hang chuc la 5: %d", TongChuc5); getch(); return 0; } ```

Output:
 ```1 2 3 4 5 6 ``` ```Line 17: error: conio.h: No such file or directory Line 6: error: expected ';', ',' or ')' before '&' token In function 'xuat': Line 26: error: 'for' loop initial declaration used outside C99 mode In function 'TinhTongSoHangChuc5': Line 52: error: 'for' loop initial declaration used outside C99 mode ```

#include<iostream>
using namespace std;
bool kt_chuc5(int n){
while(n>99) n/=10;
if(n%10==5) return true;
return false;
}
void Nhap(int n, int a[]){
for(int i=0; i<n; i++){
cout<<"a["<<i<<"]= ";
cin>>a[i];
}
}
main(){
int n;
cout<<"Nhap so phan tu cua mang: ";
cin>>n;
int a[n];
Nhap(n,a);
int tong=0;
for(int i=0; i<n; i++){
if(kt_chuc5(a[i])) tong+=a[i];
}
cout<<"Tong: "<<tong<<endl;
}