#include <stdio.h>
#include <math.h>

long state = 3;
long lcg() {
  state = (1103515245L * state + 12345L) % 2147483648L;
  return state;
}
double uniform() { return (double)lcg() / 2147483648.0; }

int main() {
  int inv = 20, reorder = 10, orderQty = 15;
  int orderDue = -1;
  double holding = 0.5, shortage = 5.0, ordering = 10.0;
  double totalCost = 0;
  int days = 100;
  for (int d = 0; d < days; d++) {
    int demand = 1 + (int)(uniform() * 5);
    if (inv >= demand) {
      inv -= demand;
      totalCost += holding * inv;
    } else {
      int lost = demand - inv;
      inv = 0;
      totalCost += shortage * lost;
    }
    if (inv <= reorder && orderDue < 0) {
      orderDue = 2;
      totalCost += ordering;
    }
    if (orderDue == 0) {
      inv += orderQty;
      orderDue = -1;
    }
    if (orderDue > 0) orderDue--;
  }
  printf("final inventory = %d\n", inv);
  printf("total cost      = %.2f\n", totalCost);
  return 0;
}