#include<stdio.h>
#include<conio.h>
#define MAX 100

void nhap (float 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("%f", &a[i]);
	}
}

void xuat(float a[], int n)
{
	for(int i = 0; i < n; i++)
	{
		printf("%8.3f", a[i]);
	}
}

float duongcuoicung(float a[], int n)
{
    for (int i = n - 1; i >= 0; i--)
    {
         if (a[i] > 0)
         {
             return a[i];
         }
    }
    return -1;
}
int main()
{
	int n;
	float a[MAX];
	nhap(a, n);
	xuat(a, n);

	float duongcuoi = duongcuoicung(a, n);
	printf("\nGia tri duong cuoi cung la %.3f", duongcuoi);

	getch();
	return 0;
}

Line 17: error: conio.h: No such file or directory
Line 5: error: expected ';', ',' or ')' before '&' token
In function 'xuat':
Line 25: error: 'for' loop initial declaration used outside C99 mode
In function 'duongcuoicung':
Line 33: error: 'for' loop initial declaration used outside C99 mode