Cod sursa(job #474038)

Utilizator daniel.dumitranDaniel Dumitran daniel.dumitran Data 2 august 2010 02:22:22
Problema Pascal Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.29 kb
#include <stdio.h>

struct desc {
  int f2, f3, f5;
};

#define LIMIT 1000000

int get_exp(int nr, int div) {
  if (!nr) return 0;
  int rez = 0;
  while ((nr % div) == 0) {
    ++rez;
    nr /= div;
  }
  return rez;
}

void get_desc(desc* d, int x) {
  d->f2 = get_exp(x, 2);
  d->f3 = get_exp(x, 3);
  d->f5 = get_exp(x, 5);
}

void mul_desc(desc* a, desc* b) {
  a->f2 += b->f2;
  a->f3 += b->f3;
  a->f5 += b->f5;
}

void div_desc(desc* a, desc* b) {
  a->f2 -= b->f2;
  a->f3 -= b->f3;
  a->f5 -= b->f5;
}

bool is_disibile(desc* a, desc *b) {
  return (a->f2 >= b->f2) && (a->f3 >= b->f3) && (a->f5 >= b->f5);
}

void print_desc(desc* a) {
  printf("[2->%d; 3->%d; 5->%d]", a->f2, a->f3, a->f5);
}

int main() {
  int r, d;
  FILE *f = fopen("pascal.in", "rt");
  fscanf(f, "%d %d", &r, &d);
  fclose(f);

  desc dd; get_desc(&dd, d);
  int rez = 0;
  int i = r;
  desc old; get_desc(&old, 0);
  for (int j = 1; j * 2 <= r; ++j) {    
    desc mul; get_desc(&mul, i - j + 1);
    desc imp; get_desc(&imp, j);
    mul_desc(&old, &mul);
    div_desc(&old, &imp);
    //    printf("j = %d old = ", j); print_desc(&old); printf("\n");
    if (is_disibile(&old, &dd)) {
      ++rez;
      if (j * 2 < r) ++rez;      
    }
  }

  f = fopen("pascal.out", "wt");
  fprintf(f, "%d\n", rez);
  fclose(f);
  
  return 0;
}