EEOJ/OJ5/main.cpp

#include <stdio.h>
#include <vector>
using namespace std;
unsigned short *neighbors[65540];
unsigned short bfsGraph[65540] = {0}; // index: to value: from
unsigned short outDegrees[65540] = {0};
unsigned short inDegrees[65540] = {0};
int nodeNum, destroyed;
template <typename T>
class Queue
{
public:
    Queue(int max);
    Queue(Queue &q);
    ~Queue();
    bool isEmpty();
    void in(T t);
    T out();

private:
    T *list;
    int max, front, tail;
    bool empty = true;
};
template <typename T>
Queue<T>::Queue(int max)
{
    list = new T[this->max = max];
    front = 0;
    tail = -1;
}
template <typename T>
Queue<T>::Queue(Queue &q)
{
    list = new T[max = q.max];
    front = 0;
    tail = -1;
    for (int i = front; (i > front && tail < front) || i <= tail; (i++) % max)
    {
        list[++tail] = q.list[i];
    }
    if (!q.isEmpty)
        empty == false;
}
template <typename T>
Queue<T>::~Queue()
{
    delete[] list;
}
template <typename T>
bool Queue<T>::isEmpty()
{
    return empty;
}
template <typename T>
void Queue<T>::in(T t)
{
    if (tail == (front - 1 + max) % max && !empty)
    {
        throw 0;
    }
    else
    {
        tail++;
        tail = tail % max;
        list[tail] = t;
        empty = false;
    }
}
template <typename T>
T Queue<T>::out()
{
    if (empty)
    {
        throw 0;
    }
    else
    {
        if (front == tail)
            empty = true;
        int tmp = front;
        front++;
        front = front % max;
        return list[tmp];
    }
}
bool bfs(int nodeNum, unsigned short delFrom = 0, unsigned short delTo = 0, bool output = false)
{
    Queue<unsigned short> q(65540);
    bool reached[65540] = {0};
    q.in(0);
    reached[0] = true;
    while (1)
    {
        if (q.isEmpty())
        {
            break;
        }
        int current = q.out();
        for (int i = 0; i < outDegrees[current]; i++)
        {
            if (current == delFrom && neighbors[current][i] == delTo)
            {
                continue;
            }
            if (reached[neighbors[current][i]])
            {
                continue;
            }
            reached[neighbors[current][i]] = true;
            q.in(neighbors[current][i]);
            if (output)
            {
                bfsGraph[neighbors[current][i]] = current;
            }
        }
    }
    for (int i = 0; i < nodeNum; i++)
    {
        if (!reached[i])
        {
            return false;
        }
    }
    return true;
}
int main()
{
    scanf("%d %d", &nodeNum, &destroyed);
    for (int i = 0; i < nodeNum; i++)
    {
        int outDegNum;
        scanf("%d", &outDegNum);
        int currentNode = i;
        outDegrees[i] = outDegNum;
        neighbors[i] = new unsigned short[outDegNum];
        for (int i = 0; i < outDegNum; i++)
        {
            int nodeNo;
            scanf("%d", &nodeNo);
            inDegrees[nodeNo] += 1;
            neighbors[currentNode][i] = nodeNo;
        }
    }
    bool connected = bfs(nodeNum, 0, 0, true);
    if (connected)
    {
        printf("1\n");
    }
    else
    {
        for (int i = 0; i < destroyed + 1; i++)
            printf("0\n");
        return 0;
    }
    for (int i = 0; i < destroyed; i++)
    {
        int from, to;
        scanf("%d %d", &from, &to);
        if (bfsGraph[to] != from)
        {
            printf("1\n");
        }
        else if (inDegrees[to] <= 1)
        {
            printf("0\n");
        }
        else
        {
            if (bfs(nodeNum, from, to, false))
                printf("1\n");
            else
                printf("0\n");
        }
    }
    return 0;
}