卡哇伊狗狗的spfa模板

const int INF = 0x3fffffff;
const int maxn = 1010;

int dis_max[maxn][maxn], dis_min[maxn][maxn];
int paces_max[maxn][maxn], paces_min[maxn][maxn];
bool visit[maxn];
int queue[maxn], n;

// flag == false 最大生成树   否则最小生成树 
void spfa(int begin, int paces[maxn], int dis[maxn], vector<Edge> edge[maxn], bool flag)
{
	int front = 0, rear = 0;
	for (int i = 1; i <= n; i++)
	{
		paces[i] = i;
		visit[i] = false;
		dis[i] = flag ? INF : -INF;
	}
	dis[begin] = 0;
	queue[rear++] = begin;
	visit[begin] = true;
	while (front != rear)
	{
		const int now = queue[front++ % maxn];
		const int size = edge[now].size();
		visit[now] = false;
		for (int i = 0; i < size; i++)
		{
			const int end = edge[now][i].end;
			const int time = dis[now] + edge[now][i].time;
			if (flag ? time < dis[end] : time > dis[end])
			{
				dis[end] = time;
				paces[end] = now;
				if (!visit[end])
				{
					visit[end] = true;
					queue[rear++ % maxn] = end;
				}
			}
		}
	}
}