#include<stdio.h>
#include<conio.h>
const int minYear = 1900, maxYear = 10000;
struct Ngay
{
	int Day, Month, Year;
};
typedef struct Ngay NGAY;

struct HopSua
{
	char NhanHieu[20];
	float TrongLuong;
	NGAY HanSuDung;
};
typedef struct HopSua HOPSUA;

bool KiemTraNamNhuan(NGAY a)
{
	return (a.Year % 4 == 0 && a.Year % 100 != 0) || (a.Year % 400 == 0);
}

bool KiemTraNamNhuan(int i)
{
    if (i % 4 == 0 && i % 100!=0)
        return true;
    if (i % 400 == 0)
        return true;
    return false;
}
int TimSoNgayTrongThang(NGAY a)
{
	int NgayTrongThang;
	switch(a.Month)
	{
	case 1: case 3: case 5: case 7: case 8: case 10: case 12:
		NgayTrongThang = 31;
		break;
	case 4: case 6: case 9 : case 11:
		NgayTrongThang = 30;
		break;
	case 2:
		int Check = KiemTraNamNhuan(a);
		if(Check == 1)
		{
			NgayTrongThang = 29;
		}
		else
		{
			NgayTrongThang = 28;
		}
	}
	return NgayTrongThang;
}


void NhapNgay(NGAY &a)
{
	do
	{
		printf("\nNhap vao nam: ");
		scanf("%d", &a.Year);
		if(a.Year < minYear || a.Year > maxYear)
		{
			printf("\nDu lieu nam khong hop le. Xin kiem tra lai!");
		}
	}while(a.Year < minYear || a.Year > maxYear);

	do
	{
		printf("\nNhap vao thang: ");
		scanf("%d", &a.Month);
		if (a.Month < 1 || a.Month > 12)
			printf("\nDu lieu thang khong hop le. Xin kiem tra lai!");
	}while(a.Month < 1 || a.Month > 12);

	int NgayTrongThang = TimSoNgayTrongThang(a);
	do
	{
		printf("\nNhap vao ngay: ");
		scanf("%d",&a.Day);
		if(a.Day < 1 || a.Day > NgayTrongThang)
		{
			printf("\nDu lieu ngay khong hop le. Xin kiem tra lai!");
		}
	}while(a.Day < 1 || a.Day > NgayTrongThang);
}


void XuatNgay(NGAY ng)
{
	printf("%d/%d/%d", ng.Day, ng.Month, ng.Year);
}

void NhapHopSua(HOPSUA &hs)
{
	fflush(stdin);
	printf("Nhap nhan hieu: \n");
	gets(hs.NhanHieu);

	printf("Nhap trong luong: \n");
	scanf("%f", &hs.TrongLuong);

	printf("Nhap han su dung: \n");
	NhapNgay(hs.HanSuDung);
}

void XuatHopSua(HOPSUA hs)
{
	printf("Nhan hieu: %s\n", hs.NhanHieu);
	printf("Trong luong: %.2f(kg)\n", hs.TrongLuong);
	printf("Han su dung: \n");
	XuatNgay(hs.HanSuDung);
}
int main()
{
	HOPSUA a;
	NhapHopSua(a);
	XuatHopSua(a);
	getch();
	return 0;
}

Line 17: error: conio.h: No such file or directory
Line 18: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'KiemTraNamNhuan'
Line 23: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'KiemTraNamNhuan'
In function 'TimSoNgayTrongThang':
Line 43: error: expected expression before 'int'
Line 44: error: 'Check' undeclared (first use in this function)
Line 44: error: (Each undeclared identifier is reported only once
Line 44: error: for each function it appears in.)
t.c: At top level:
Line 57: error: expected ';', ',' or ')' before '&' token
Line 95: error: expected ';', ',' or ')' before '&' token