#include <stdio.h>
#include<conio.h>
void main()
{ int ngay , thang , nam,s=0,x; long t;
do
{ printf("Nhap vao Ngay :");
scanf("%d",&ngay);
printf("Nhap vao Thang :");
scanf("%d",&thang);
printf("Nhap vao Nam :");
scanf("%d",&nam); } while(((ngay<0)||(ngay>31)||(thang<0)||(thang>12))||((thang==2)&&(ngay>29)));
for(int i=1;i<=nam;i++)
{ if((i%400==0)||((i%4==0)&&(i%100!=0))) s+=1; }
t=(nam*365)+s;
s=0;
for(int j=1;j<thang;j++)
{
switch(j)
{ case 2: if ((nam%400==0)||((nam%4==0)&&(nam%100!=0))) { s+=29; break; } else { s+=28; break; }
case 4: case 6: case 9: case 11: s+=30; break; default: s+=31; break;}
}
t+=s+ngay;
textcolor(6-9); x=t%7;
printf("\n\n Ngay %d Thang %d Nam %d La Ngay ",ngay,thang,nam);
switch(x)
{ case 0: cprintf("Chu Nhat "); break;
case 1: cprintf("Thu Hai "); break;
case 2: cprintf("Thu Ba "); break;
case 3: cprintf("Thu Tu "); break;
case 4: cprintf("Thu Nam "); break;
case 5: cprintf("Thu Sau "); break;
case 6: cprintf("Thu Bay "); break;
}
getch();
}