#include <stdlib.h>

int factorielle(int nbre);
int arrang(int n, int p);
int combi(int n, int p);

int main()
{
  int chx;
  do{
  //MENU
  printf("Choisissez le calcul a realiser\n");
  printf("1 : Factorielle\n");
  printf("2 : Arrangement\n");
  printf("3 : Combinaison\n");
  printf("4 : Quitter\n");
  scanf("%d", &chx);
  switch(chx){
    case 1:{
      int nbre=0;
      printf("Entrez le nombre pour la factorielle :\n");
      scanf("%d",&nbre);
      printf("La factorielle vaut %d\n", factorielle(nbre));
      break;
    }
    case 2:{
      int n,p;
      printf("Entrez N\n");
      scanf("%d", &n);
      printf("Entrez P\n");
      scanf("%d",&p);
      printf("L'arrangement de %d par %d vaut: %d\n", n, p, arrang(n,p));
      break;
    }
    case 3:{
      int n,p;
      printf("Entrez N\n");
      scanf("%d", &n);
      printf("Entrez P\n");
      scanf("%d",&p);
      printf("La combinaison de %d par %d vaut: %d\n", n, p, combi(n,p));
      break;
    }
    case 4:{
      return 0;
    }
  }
  }while(chx!=4);
}


/************************************************/
int factorielle(int nbre)
{
  int res=nbre, i;
  for(i=nbre-1; i!=0; i--){
    res = res*i;
  }
  return (res);
}
/************************************************/
int arrang(int n, int p)
{
  int res,nbre, numer,denom;
  nbre= n;
  numer= factorielle(nbre);
  denom= factorielle(nbre-p);
  res= numer/denom;
  return (res);
}
/************************************************/
int combi(int n, int p)
{
  int res, numer, denom, a, b;

  numer= factorielle(n);
  a= factorielle(n-p);
  b= factorielle(p);
  denom= a*b;
  res= numer/denom;

  return (res);
}