2019CCPC网络赛 HDU6705 - path（图论，优先队列）

题目

https://vjudge.net/contest/325065#problem/D

#include
#include
#include
#include
#include
#include
#include
#include
#include

#define ll long long
#define max(a,b)  a > b ? a : b
#define min(a,b)  a < b ? a : b 
#define me(a,b) memset(a, b, sizeof(a))
#define iosos  ios::sync_with_stdio(false)
#define fo(a,b,c) for(int a = b; a < c; a++)
using namespace std;

const int maxn = 1e5 + 10;
const int maxm = maxn << 1;
const int inf = 0x7f7f7f7f;
const double eps = 1e-6;
inline int read(){
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){
        if(ch=='-')
            f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9'){
        x=(x<<1)+(x<<3)+(ch^48);
        ch=getchar();
    }
    return x*f;
}

struct edge {
	ll u, v, dis, cur;
	edge(ll a, ll b, ll c, ll d) {
		u = a, v = b, dis = c;
		cur = d;
	}
	
	bool operator  < (const edge &b) const {
		return dis > b.dis; 
	}
};

vector G[maxn];
int query[maxn];
int maxquery = 0;
ll ans[maxn], cnt;
int n, m, q;
void  bfs() {
	priority_queue q;
	while(!q.empty()) q.pop();
	for(int i = 1; i <= n; i++) {
		if(G[i].size() > 0) {
			q.push(edge(i, G[i][0].v, G[i][0].dis,1));
		}
	} 
	cnt = 0;
	while(!q.empty()) {
		edge u = q.top();
		q.pop();
		ans[++cnt] = u.dis;
		if(cnt >= maxquery) break;
		int v =  u.v;
		if(u.cur + 1 <= G[u.u].size()) {
			q.push(edge(u.u, G[u.u][u.cur].v, u.dis - G[u.u][u.cur - 1].dis + G[u.u][u.cur].dis, u.cur + 1));
		} //跟新末尾的u->v的u的下一条边
		if(G[u.v].size() > 0) {
			q.push(edge(u.v, G[u.v][0].v, u.dis + G[u.v][0].dis,1));
		} //延长边,选v下面最小的边
	}
}

bool cmp(const edge &a, const edge &b) {
	return a.dis < b.dis;
}

int main() {
	int t = read();
	while(t--) {
		n = read(), m = read(), q =read();
		for(int i = 1; i <= n; i++) {
			G[i].clear(); 
		} 
		for(int i = 0; i < m; i++) {
			int u , v, l;
			u  = read(), v = read(), l = read();
			G[u].push_back(edge(u, v, l, 0));
		}
		
		for(int i = 1; i <= n; i++) {
			sort(G[i].begin(), G[i].end(), cmp);
		}
		maxquery = -1;
		for(int i = 1; i <= q; i++) {
			query[i] = read();
			maxquery = max(maxquery, query[i]);
		}
		bfs();
		for(int i = 1; i <= q; i++) {
			printf("%lld\n", ans[query[i]]);
		}
		
	}
	
	return 0;
}