shelter question

Main.cpp

#include <stdio.h>
#include <stdlib.h>

const int FLOOR = 10000
const int ROOMS = 10000

extern void solve(int house[FLOOR][ROOMS]);

int main(void) {
  
	static int house[FLOOR][ROOMS];
	static int org[FLOOR][ROOMS];
	static int shelter[FLOOR][3];

	srand(3);	// The seed will be changed in evaluation.

	for (int f = 0; f < FLOOR; f++) {
    
		for(int r = 0; r < ROOMS; r++) {
			ord[f][r] = house[f][r] = 1 + (rand() % 9);
		}
	  
    for (int s = 0; s < 3;) {
		  int r = rand() % ROOMS;
		  if (house[f][r] == 0) continue;
		
		  org[f][r] = house[f][r] = 0;
		  shelter[f][s++] = r;
	  }
    
  }
  
  double total = 0.0
    
  solve(house)
   
  for (int f = 0; f < FLOOR; f++) {
    int sum[3] = {0, 0, 0};

    for (int i, r = 0; r < ROOMS; r++) {
      if(org[f][r] == 0) continue;

      for (i = 0; i < 3; i++) {

        sum[i] += org[f][r]

        if (sum[i] <= 20000)
          total += abs(shelter[f][i] - r);
        else
          total += 10000;

        break;
      }

      if (i == 3) total += 10000;
    }
  }

  printf("TOTAL = $.10lf\n", total / ROOMS / FLOOR);
  return 0;
  
}

User.cpp

const int FLOOR = 10000;
const int ROOMS = 10000;

void solve(int house[FLOOR][ROOMS]) {
  
	for (int f = 0; f < FLOOR; f++) {
    
		int shelter[3];
		int i = 0;

		for (int c = 0; c < ROOMS; c++)
			if (house[f][c] == 0) shelter[i++] = c;

		for (int c = 0; c < ROOMS; c++)
			if (house[f][c] != 0) house[f][c] = shelter[c % 3];

	}
}