美团2018年CodeM大赛-初赛B轮 B 配送

美团2018年CodeM大赛-初赛B轮 B 配送

题意

题解

代码

#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define rep(i, a, b) for(int i=(a); i<(b); i++)
#define sz(a) (int)a.size()
#define de(a) cout << #a << " = " << a << endl
#define dd(a) cout << #a << " = " << a << " "
#define all(a) a.begin(), a.end()
#define endl "\n"
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
//---

const int inf = 2e9;

int n, m, k;
struct Task {
    int pos;
    string tim;
    bool operator < (const Task &c) const {
        return tim < c.tim;
    }
}task[11];
struct Edge {
    int v, p;
    string st, ed;
    Edge(int v, int p, string st, string ed) : v(v), p(p), st(st), ed(ed) {}
};
vector<Edge> g[111];
map<string, int> dis[111];

void dij(int pos, string tim) {
    rep(i, 1, k+1) dis[i].clear();
    dis[pos][tim] = 0;
    priority_queue<pair<int, pair<int, string> > > que;
    que.push(mp(0, mp(pos, tim)));
    while(!que.empty()) {
        auto u = que.top(); que.pop();
        int d = -u.fi;
        pos = u.se.fi; tim = u.se.se;
        if(d != dis[pos][tim]) continue;
        for(auto i : g[pos]) {
            int v = i.v, p = i.p;
            int t = dis[pos][tim] + p;
            if(tim < i.st && (!dis[v].count(i.ed) || dis[v][i.ed] > t)) {
                dis[v][i.ed] = t;
                que.push(mp(-t, mp(v, i.ed)));
            }
        }
    }
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    cin >> n >> m >> k;
    rep(i, 0, n) {
        string s1, s2;
        cin >> task[i].pos >> s1 >> s2;
        task[i].tim = s1 + " " + s2;
    }
    sort(task, task+n);
    rep(i, 0, m) {
        int u, v, p;
        string st, ed;
        cin >> u >> v >> p >> st >> ed;
        rep(j, 1, 8) {
            string t1 = "2018.07.0" + to_string(j) + " " + st;
            string t2 = "2018.07.0" + to_string(j) + " " + ed;
            g[u].pb(Edge(v, p, t1, t2));
        }
    }
    int pos = 1, ans = 0;
    string tim = "2018.06.30 23:59:59.999";
    rep(i, 0, n) {
        dij(pos, tim);
        int res = inf;
        for(auto j : dis[task[i].pos]) {
            if(j.fi < task[i].tim) res = min(res, j.se);
            else break;
        }
        if(res == inf) {
            ans = inf;
            break;
        }
        ans += res;
        pos = task[i].pos;
        tim = task[i].tim;
    }
    if(ans == inf) ans = -1;
    cout << ans << endl;
    return 0;
}