#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <string.h>

struct DATE
{
	int ngay, thang, nam;
};

struct SV
{
	char MSSV [15];
	char hoTen [50];
	DATE ns;
	float diemTB;
};

void nhap1SV (SV &x)
{
	printf("\nMSSV: ");		fflush (stdin);		scanf("%s", &x.MSSV);
	printf("Ho ten: "); 	fflush (stdin);
	gets(x.hoTen);
	
	printf("Ngay/thang/nam sinh: ");
	scanf("%02d %*c %02d %*c %4d", &x.ns.ngay, &x.ns.thang, &x.ns.nam);
	
	printf("Diem TB: ");	scanf("%f", &x.diemTB);
	
}

void nhapDSSV (SV x[], int &n)
{
	fflush(stdin);
	for(int i=0; i<n; i++)
	{
		printf("\nNhap SV thu %d", i+1);
		nhap1SV(x[i]);
	}
}


void xuatDSSV (SV x[], int n)
{
		printf("\nMSSV \t\t\t Ho ten \t\t\t Ngay sinh \t\t DiemTB");
	for (int i=0; i<n; i++)
	{		

		printf("\n%s \t\t\t %s \t\t\t\t %02d/%02d/%4d \t\t %f", x[i].MSSV, x[i].hoTen, x[i].ns.ngay, x[i].ns.thang, x[i].ns.nam, x[i].diemTB);
		printf("\n------------------------------------------------------------------------------");
	}
}

void timThongTinTheoMSSV (SV x[], int n)
{
	int i=0;
	char MaSo [15];
	printf("\n\tTIM KIEM THONG TIN SV THEO MSSV");
	printf("\nNhap MSSV: ");
	fflush(stdin);
	gets(MaSo);
	
	printf("\nDanh sach SV duoc tim thay la: ");
	
	for(int i=0; i<n; i++)
		if (strcmp(x[i].MSSV, MaSo) == 0)
			{ 
				printf("\nMSSV \t\t Ho ten \t\t Ngay sinh \t\t DiemTB");
				printf("\n%s \t\t %s ", x[i].MSSV, x[i].hoTen);
				printf("\t\t %02d/%02d/%4d \t\t%2.1f", x[i].ns.ngay, x[i].ns.thang, x[i].ns.nam, x[i].diemTB);	
				
				break;
			}
		if (i == n) 	printf("Khong tim thay SV nao.");
}

void suaDiem(SV x[], int n)
{
	int i=0;
	char MaSo [15];
	
	printf("\n------------------------------------------------------------------------------");
	printf("\n\t TIM SV DUA VAO MSSV, SUA LAI DIEMTB");
	printf("\nNhap MSSV: ");
	fflush(stdin);
	gets(MaSo);
	
	for(int i=0; i<n; i++)
		if (strcmp(x[i].MSSV, MaSo) == 0)
		{
			printf("\nNhap lai diem TB: ");
			scanf("%f", &x[i].diemTB);
		}
		if (i==n)	printf("Khong tim thay SV nao.");
}

void sapXepTheoMSSV(SV x[], int n)
{
	SV a;
	int i,j;
	
	for (int i=0; i<n-1; i++)
		for (int j=i+1; j<n; j++)
			if (strcmp (x[i].MSSV, x[j].MSSV) > 0)
			{
				a = x[i];
				x[i] = x[j];
				x[j] = a;
			}
}

void sapXepTheoDTB(SV x[], int &n)
{
	SV tmp;
	int i, j;
	for (i=0; i<n-1; i++)
		for (j=0; j<n; j++)
			if (x[i].diemTB > x[j].diemTB)
			{
				tmp = x[i];
				x[i] = x[j];
				x[j] = tmp;
			}
}

void timAvaXoaTheoMSSV (SV x[], int &n, char MaSo[])
{

	printf("\n------------------------------------------------------------------------------");
	printf("\n\t\t TIM SV BANG MSSV, XOA SV RA KHOI DANH SACH");
	printf("\nNhap MSSV: ");
	fflush(stdin);
	gets(MaSo);
	
	for(int i=0; i<n; i++)
	if (strcmp (x[i].MSSV, MaSo) == 0)
	{
		// xoa SV thu i
		for (int j=0; j<n-1; j++)
			x[i] = x[j+1];
			
		// xoa xong
		printf("\nDanh sach sv con lai la: ");
		n--;
		return;
	}
	printf("\n\nTrong DSSV khong co ma A nay!");
}

int main()
{
	SV x[15];
	int n, chon;
	char maMuonXoa [15];
	
	while (true)
	{	
		printf("\n\t----CHUONG TRINH QUAN LY SINH VIEN C----");

		printf("\n\t 1. Xuat danh sach SV");
		printf("\n\t 2. Sua diem cua mot SV bat ky");
		printf("\n\t 3. Tim kiem thong tin SV dua vao viec nhap MSSV");
		printf("\n\t 4. Sap xep SV theo MSSV");
		printf("\n\t 5. Sap xep thu hang SV theo DTB");
		printf("\n\t 6. Xoa SV ra khoi danh sach dua tren MSSV");
		printf("\n\t 0. Thoat. ");
		printf("\n\t--------------------------------------------------");
			
		do
		{
			printf("\nNhap so luong SV (0<n<=15): ");
			scanf("%d", &n);
		} while (n<=0 || n>15);
		
			printf("\n\tNHAP DANH SACH SV");
			nhapDSSV(x,n);
			

		printf("\n\nNhap tuy chon: ");
		fflush(stdin);
		scanf("%d", &chon);
		
		switch(chon)
		{
				
		case 1: 
			printf("\n\t 1.XUAT DANH SACH SV\n");
			xuatDSSV(x,n);
			printf("\nNhan 1 phim bat ky de tiep tuc.\n");
			getch();
			break;
			
		case 2: 
			printf("\n\t 2. SUA DIEM CUA MOT SINH VIEN BAT KY\n");
			suaDiem(x,n);
			xuatDSSV(x,n);
			printf("\nNhan 1 phim bat ky de tiep tuc.\n");
			getch();
			break;
			
		case 3: 
			printf("\n\t 3. TIM KIEM THONG TIN SV DUA VAO VIEC NHAP MSSV\n");
			timThongTinTheoMSSV(x,n);
		//	xuatDSSV(x,n);
			printf("\nNhan 1 phim bat ky de tiep tuc.\n");
			getch();
			break;
			
		case 4:
			printf("\n\t 4. SAP XEP SV THEO MSSV\n");
			sapXepTheoMSSV(x,n);
			xuatDSSV(x,n);
			printf("\nNhan 1 phim bat ky de tiep tuc.\n");
			getch();
			break;
			
		case 5:
			printf("\n\t 5. SAP XEP THU HANG SV THEO DTB\n");
			sapXepTheoDTB(x,n);
			xuatDSSV(x,n);
			printf("\nNhan 1 phim bat ky de tiep tuc.\n");
			getch();
			break;
			
		case 6:
			printf("\n\t 6. XOA SV RA KHOI DS DUA TREN MSSV\n");
			timAvaXoaTheoMSSV(x,n,maMuonXoa);
			xuatDSSV(x,n);
			printf("\nNhan 1 phim bat ky de tiep tuc.\n");
			break;
			
		case 0:
			printf("\nBan da chon thoat chuong trinh!");
			getch();
			return 0;
			
		default:
			printf("\nKhong co chuc nang nay!");
			printf("\nHay chon chuc nang hop le!");
			break;
		}
	
	}
	return 1;
}