bzoj1922 [Sdoi2010]大陆争霸 最短路

题目传送门

https://lydsy.com/JudgeOnline/problem.php?id=1922

题解

没什么好写的，又被骗了，本篇文章只用于挂挡。

#include<bits/stdc++.h>

#define fec(i, x, y) (int i = head[x], y = g[i].to; i; i = g[i].ne, y = g[i].to)
#define dbg(...) fprintf(stderr, __VA_ARGS__)
#define File(x) freopen(#x".in", "r", stdin), freopen(#x".out", "w", stdout)
#define fi first
#define se second
#define pb push_back

template<typename A, typename B> inline char smax(A &a, const B &b) {return a < b ? a = b, 1 : 0;}
template<typename A, typename B> inline char smin(A &a, const B &b) {return b < a ? a = b, 1 : 0;}

typedef long long ll; typedef unsigned long long ull; typedef std::pair<ll, int> pii;

template<typename I> inline void read(I &x) {
	int f = 0, c;
	while (!isdigit(c = getchar())) c == '-' ? f = 1 : 0;
	x = c & 15;
	while (isdigit(c = getchar())) x = (x << 1) + (x << 3) + (c & 15);
	f ? x = -x : 0;
}

const int N = 3000 + 7;
const int M = 70000 + 7;
const int INF = 0x3f3f3f3f;

int n, m;
std::vector<int> v[N];
int vis[N], deg[N];
ll dis[N], dis2[N];
std::priority_queue<pii, std::vector<pii>, std::greater<pii> > q;

struct Edge { int to, ne, w; } g[M]; int head[N], tot;
inline void addedge(int x, int y, int z) { g[++tot].to = y, g[tot].w = z, g[tot].ne = head[x], head[x] = tot; }
inline void adde(int x, int y, int z) { addedge(x, y, z), addedge(y, x, z); }

inline void dijkstra() {
	memset(dis, 0x3f, sizeof(dis));
	dis[1] = 0, q.push(pii(0, 1));
	while (!q.empty()) {
		int x = q.top().se; q.pop();
		if (vis[x]) continue;
		vis[x] = 1, smax(dis[x], dis2[x]);
		if (x == n) return;
		int len = v[x].size();
		for (int i = 0; i < len; ++i) {
			int y = v[x][i];
			smax(dis2[y], dis[x]), --deg[y];
			if (!deg[y] && dis[y] != INF) q.push(pii(std::max(dis[y], dis2[y]), y));
		}
		for fec(i, x, y) if (smin(dis[y], dis[x] + g[i].w) && !deg[y]) q.push(pii(std::max(dis[y], dis2[y]), y));
	}
}

inline void work() {
	dijkstra();
	printf("%lld
", dis[n]);
}

inline void init() {
	read(n), read(m);
	int x, y, z;
	for (int i = 1; i <= m; ++i) read(x), read(y), read(z), addedge(x, y, z);
	for (int i = 1; i <= n; ++i) {
		int l, x;
		read(l);
		while (l--) read(x), v[x].pb(i), ++deg[i];
	}
}

int main() {
#ifdef hzhkk
	freopen("hkk.in", "r", stdin);
#endif
	init();
	work();
	fclose(stdin), fclose(stdout);
	return 0;
}