hdu 5876 Sparse Graph bfs 鏈表優化

題意：求圖的補圖，然後給定s，求s到各點的最短路

思路：暴力bfs，用鏈表優化，邊數題目給少了，不知道爲什麼會超時，不是顯示RE?

鏈接：http://acm.hdu.edu.cn/showproblem.php?pid=5876

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;

const int maxn = 200005;

struct edge
{
    int u, v, next;
} e[20005];
int head[maxn], cnt;

void init()
{
    cnt = 0;
    memset(head, -1, sizeof(head));
}

void addedge(int u, int v)
{
    e[cnt].u = u, e[cnt].v = v, e[cnt].next = head[u], head[u] = cnt++;
}

int n, m, s;
int d[maxn];
bool vis[maxn], inq[maxn];
struct node
{
    int pre, next;
} l[maxn];

void del(int pos)
{
    l[l[pos].pre].next=l[pos].next;
    l[l[pos].next].pre=l[pos].pre;
}

void bfs()
{
    queue<int> q;
    memset(d, 0, sizeof(d));
    memset(vis, false, sizeof(vis));
    memset(inq, false, sizeof(inq));
    q.push(s);
    inq[s] = true;
    while(!q.empty())
    {
        int u = q.front();
        q.pop();
        for(int i = head[u]; i != -1; i = e[i].next) vis[e[i].v] = true;
        for(int i = l[0].next; i != 0; i = l[i].next)
        {
            if(!vis[i] && !inq[i])
            {
                inq[i] = true;
                q.push(i);
                d[i] = d[u] + 1;
                del(i);
            }
        }
        for(int i = head[u]; i != -1; i = e[i].next) vis[e[i].v] = false;
    }
}

int main()
{
    int t;
    scanf("%d", &t);
    while(t--)
    {
        scanf("%d%d", &n, &m);
        init();
        for(int i = 0; i < m; i++)
        {
            int u, v;
            scanf("%d%d", &u, &v);
            addedge(u, v);
            addedge(v, u);
        }
        scanf("%d", &s);
        for (int i = 1; i <= n; i++)
        {
            l[i - 1].next = i;
            l[i].pre = i - 1;
        }
        l[n].next = 0;
        bfs();
        if(s == n) n--;
        for(int i = 1; i <= n; i++)
        {
            if(i != s)
                printf("%d%c", d[i] == 0 ? -1 : d[i], i == n ? '\n' : ' ');
        }
    }
    return 0;
}