//Trecerea unui numar din baza 10 in baza oarecare a
#include <stdio.h>
#include <conio.h>
#include <math.h>
int a;

void baza(int n,long x,int k)
{
 int r=n-n/a*a;
 x=x+r*pow(10,k);
 n=n/a;
 if (n==0) {printf("%ld",x);return;}
 else baza(n,x,k+1);
}

void main()
{
 clrscr(); int n;
 printf("\nnr=");scanf("%d",&n);
 printf("\nBaza=");scanf("%d",&a);
 baza(n,0,0);
 getch();
}

//trecerea unui numar dintr-o baza oarecare a in baza 10
#include <stdio.h>
#include <conio.h>
#include <math.h>
int a;

void baza(long n,long x,int k)
{
 long r=n-n/10*10;
 x=x+r*pow(a,k);
 n=n/10;
 if (n==0) {printf("%ld",x);return;}
 else baza(n,x,k+1);
}

void main()
{long n;
 clrscr();
 printf("\nBaza=");scanf("%d",&a);
 printf("\nnr=");scanf("%ld",&n);
 baza(n,0,0);
 getch();
}
//Trecerea unui numar din baza 10 in baza oarecare a
#include <stdio.h>
#include <conio.h>
#include <math.h>
int a,b;

void baza10b(long n,long x,int k)
{
 long r=n-n/b*b;
 x=x+r*pow(10,k);
 n=n/b;
 if (n==0) printf("\n%ld",x);
 else baza10b(n,x,k+1);
}

void baza(long n,long x,int k)
{
 long r=n-n/10*10;
 x=x+r*pow(a,k);
 n=n/10;
 if (n==0) baza10b(x,0,0);
 else baza(n,x,k+1);
}

void main()
{
 clrscr(); long n;
 printf("\nnr=");scanf("%d",&n);
 printf("\nBazele:");scanf("%d%d",&a,&b);
 baza(n,0,0);
 getch();
}

//Trecerea unui numar din baza a in baza oarecare b
#include <stdio.h>
#include <conio.h>
#include <math.h>
int a,b;

void baza10b(long n,long x,int k)
{
 long r=n-n/b*b;
 x=x+r*pow(10,k);
 n=n/b;
 if (n==0) printf("\n%ld",x);
 else baza10b(n,x,k+1);
}

void baza(long n,long x,int k)
{
 long r=n-n/10*10,re;
 printf("\nr=%ld",r);
 do{
  printf("\nr=%ld,x=%ld",r,x);
  re=r-r/b*b;
  x=x+re*pow(10,k);
  r=r/b;  k++;
  }while(r!=0);
 n=n/10;
 if (n==0) printf("\n%ld",x);
 else baza(n,x,k);
}

void main()
{
 clrscr(); long n;
 printf("\nnr=");scanf("%ld",&n);
 printf("\nBazele:");scanf("%d%d",&a,&b);
 baza(n,0,0);
 getch();
}

///schimbare baza fara trecere in baza 10
#include <stdio.h>
#include <math.h>
#include <conio.h>
void main()
       {
	int  nr,baza,r,nrf,k,N;
	int baza1;
	nrf=0;
	k=0;
	clrscr();
	printf("\n Dati baza de pornire :");
	scanf("%d",&baza);
	printf("\n Dati numarul in baza %d :",baza);
	scanf("%d",&nr);
	N=nr;
	printf("\n Dati baza rezultat :");
	scanf("%d",&baza1);
	while(nr!=0)
		{
		r=nr-int(nr/baza1)*baza1;
		nrf=nrf+r*pow(baza,k);
		nr=nr/baza1;
		if(nr!=0)
			k=k+1;
		}
	printf("\n Numarul %d se scrie in baza %d  :  %d",N,baza1,nrf);
	getch();
	}