C, pasted on Oct 9:
 ```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 ``` ```#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]); } } void LietKeTanSuatXuatHien(int a[], int n) { for(int i = 0; i < n; i++) { int dem = 0; for(int j = 0; j < n; j++) // j chạy từ 0 { if(a[i] == a[j]) { if(i <= j) { dem++; } else { break; // bỏ qua phần tử bị trùng } } } if(dem != 0) { printf("\nGia tri %d co tan suat xuat hien la %d", a[i], dem); } } } int main() { int n; int a[MAX]; nhap(a, n); xuat(a, n); LietKeTanSuatXuatHien(a, n); getch(); return 0; } ```

Output:
 ```1 2 3 4 5 6 7 ``` ```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 'LietKeTanSuatXuatHien': Line 35: error: 'for' loop initial declaration used outside C99 mode Line 38: error: 'for' loop initial declaration used outside C99 mode ```