Tanie hotele(SPOJ)

Poproszę o pomoc w tym zadaniu, nie mogę znaleźć testów dla których mój kod daje błędną odpowiedź.

Link do zadania: http://pl.spoj.com/problems/HOT/

Kod:

#include <stdio.h>
#include <vector>

using namespace std;

struct hotel{
	int price;
	int dist;
};

int main() {
	int distance, count, lastDist = 0;
	scanf("%i%i", &distance, &count);
	vector<hotel> hotels;
	hotel start;
	start.dist = 0;
	start.price = 0;
	hotels.push_back(start);
	while (count--) {
		vector<hotel> newHotels;
		int dist, price;
		scanf("%i%i", &dist, &price);
		int deltaDist = dist - lastDist;
		for (int i = 0; i < hotels.size(); i++) {
			hotel stay, pass;
			stay.price = hotels[i].price + price;
			stay.dist = 0;
			pass.price = hotels[i].price;
			pass.dist = hotels[i].dist + deltaDist;
			newHotels.push_back(stay);
			if(pass.dist < 800)
				newHotels.push_back(pass);
		}
		hotels = newHotels;
		lastDist = dist;
	}
	for (int i = 0; i < hotels.size(); i++) {
		if (hotels[i].dist + distance - lastDist > 800) {
			hotels[i] = hotels[hotels.size() - 1];
			hotels.pop_back();
			i--;
		}
	}
	int lowestPrice = hotels[0].price;
	for (int i = 1; i < hotels.size(); i++) {
		if (hotels[i].price < lowestPrice)
			lowestPrice = hotels[i].price;
	}
	printf("%i", lowestPrice);
}