568 - Just the facts/568.cpp

   1 #include <stdio.h>
   2
   3
   4 int main(){
   5   int f[10001];
   6   f[1] = 1;
   7   for (int i = 2; i <= 10000; ++i){
   8     f[i] = f[i-1]*i;
   9     while (f[i]%10 == 0) f[i] /= 10;
  10     f[i] %= 100000;
  11     //printf("f[%d] es %d\n", i, f[i]);
  12   }
  13
  14   int n;
  15   while (scanf("%d", &n) == 1){
  16     printf("%5d -> %d\n", n, f[n]%10);
  17   }
  18   return 0;
  19 }