Chua bai 2-de cuong (duoc sua lai)

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

void nhapin(unsigned a[], int *n)
{
int t,i=0;
do
{
printf( "a[%d]= ",i+1);
scanf("%d",&t);
if (t!=0)
{
a[i]=t;
*n=i+1;
}
i++;
} while (t != 0);
}

void sapxep(unsigned a[], int n)
{
int i, j, tg;
for(i =0; i<n; i++)
for(j =i+1; j<n; j++)
{
if(a[i] < a[j])
{
tg = a[i];
a[i] = a[j];
a[j] = tg;
}
}
for(i =0; i<n; i++)
printf(" %u ", a[i]);
}

long luythuanhiphan(int j, int b)
{
long tam;
int i;
tam=1;
for (i=1;i<j;i++)
tam=tam*b ;
return tam;
}
long luythuacosokhac(int k, int b)
{
long lt=1;
for(int i=0;i<=k;i++)
{
lt=lt*b;
}
return lt;
}

long chuyendoi(char d[],int b)
{
int k,i;
char x[1];
long tp;
k=0; tp=0;
if (b==2)//Neu la so nhi phan
{
for(i=strlen(d);i>=0;i--)
{
if (d[i]=='1')
tp=tp+luythuanhiphan(k,b);
k++;
}
}
else // la co so khac
{
x[0]=d[strlen(d)-1];
tp=tp+atol(x);
int t=strlen(d)-2 ;
for(int i=0;i<=strlen(d)-2;i++)
{
x[0]=d[i];
tp=tp+atol(x)*luythuacosokhac(t,b); //ham atol chuyen xau thanh so
t--;
}
}
return tp ;
}


void main()
{
char d[20];
unsigned a[50];

int b,n, chon=0;
while(chon < 3)
{
clrscr();
printf("\n ************ BAI THI MON EPC ***************\n\n");
printf("********************************************************************");
printf("\n");
printf("* Ngay thang nam sinh: ___________________________________________ *");
printf("\n");
printf("* Ten sinh vien: _________________________________________________ *");
printf("\n");
printf("* Ma so sinh vien: _______________________________________________ *");
printf("\n");
printf("*_________________________________________________________________ *");
printf("\n");
printf("* Xin moi ban chon 1 trong 3 lua chon sau:________________________ *");
printf("\n");
printf("* 1. Bai tap 2. *\n");
printf("* 2. Bai tap 3. *\n");
printf("* 3. Thoat chuong trinh. *\n");
printf("********************************************************************");

printf("\n\n Ban chon: ");
scanf("%d", &chon);

switch (chon)
{
case 1:

clrscr();
printf("\n Nhap co so dem: ");
scanf("%d", &b);
printf("\n Co so can chuyen: ");
scanf("%s", &d);
if (b==10) //neu la so thap phan thi in ngay
printf("So thap phan la: %s", d);
else
printf("So vua chuyen la:%ld",chuyendoi(d, b));
getch();
break;

case 2:

clrscr();
printf("\n Tong so nguyen duong nhap: ");
nhapin(a,&n );
getch();
printf("\n\n\n Danh sach sau khi sap xep: ");
sapxep(a, n);
getch();
break;
}
}
getch();
}

Dạ cảm ơn thầy!Hoá ra la dùng luỹ thừa.Thế mà em ko nghĩ ra là dùng luỹ thừa thì sẽ làm được cái công thức chung.

chan qua... em thi lai la cai chac roi.. kho hieu the khong biet... nan. thoi thi danh vay. tai mai choi qua. tu mai cay thi lai thoi . hoc lai thi vo mom...