L3-005 垃圾箱分布

#include <bits/stdc++.h>

using namespace std;

using pii = pair<int, int>;

const int N = 1210, M = 15;
int n, m, k, ds;
unordered_map<string, int> var;
unordered_map<int, string> local;
vector<pair<int, int>> g[N];
int dist[N];
bool st[N];

struct Z{
    int d;
    double aver;
    int var;
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    for (int i = 1; i <= 10; i++) {
        string v = "G" + to_string(i);
        var[v] = i + 1000;
        local[i + 1000] = v;
    }

    cin >> n >> m >> k >> ds;
    for (int i = 0; i < k; i++) {
        string a, b;
        int w;
        cin >> a >> b >> w;
        int aa, bb;
        if (a[0] == 'G') {
            aa = var[a];
        } else aa = stoi(a);
        if (b[0] == 'G') {
            bb = var[b]; 
        } else bb = stoi(b);
        g[aa].push_back({bb, w});
        g[bb].push_back({aa, w});
    }

    int res1 = -1;
    double resmindist = -1, resaver = 1e9;
    for (int i = 1; i <= m; i++) {
        int ljvar = i + 1000;
       // cout << local[ljvar] << "\n";
        memset(dist, 0x3f, sizeof dist);
        memset(st, false, sizeof st);
        priority_queue<pii, vector<pii>, greater<pii>> heap;
        dist[ljvar] = 0;
        heap.push({dist[ljvar], ljvar});
        while (heap.size()) {
            auto t = heap.top();
            heap.pop();

            int u = t.second;
            if (st[u]) continue;
            st[u] = true;
            for (auto itr : g[u]) {
                int v = itr.first, w = itr.second;
                if (dist[v] > dist[u] + w) {
                    dist[v] = dist[u] + w;
                    heap.push({dist[v], v});
                }
            }
        }
        //1. 所有居民点最短距离最长 输出
        //2. 平均距离最短 输出
        //3. 编号最小 输出
        int d = 0;
        bool ok = 1;
        int mindist = 1e9;
        for (int j = 1; j <= n; j++) {
            if (dist[j] == 0x3f3f3f3f || dist[j] > ds) { //未到达 或者距离不满足
                ok = 0;
                continue;
            }
            d += dist[j];
            mindist = min(mindist, dist[j]);
        }

        //cout << "d == " << d << " mindist = " << mindist << " resaver = " << resaver << "\n";

        double av = 1.0 * d / (1.0 * n);
        if (!ok) continue;
        if (resmindist < mindist) {
            resmindist = mindist;
            res1 = ljvar;
            resaver = av;                
        } else if (resmindist == mindist) {
            if (resaver > av) {
                res1 = ljvar;
                resaver = av;
            } 
        }
        
    }

    if (res1 == -1) cout << "No Solution";
    else {
        cout << local[res1] << "\n";
        cout << fixed << setprecision(1) << resmindist << " " << resaver;
    }
    
    cout << "\n";

    return 0;
}