[20250930] BOJ / P3 / Alternative Mart / 권혁준

Author: oncsr

khj20006/202509/30 BOJ P3 Alternative Mart.md

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+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+
+int N, M, K, Q;
+vector<vector<pair<int, int>>> V(50001);
+vector<deque<pair<int, int>>> D(50001);
+priority_queue<tuple<int, int, int>, vector<tuple<int, int, int>>, greater<>> PQ;
+
+int main() {
+    cin.tie(0)->sync_with_stdio(0);
+
+    for (cin >> N >> M >> K >> Q; K--;) {
+        int a;
+        cin >> a;
+        PQ.emplace(0, a, a);
+        D[a].emplace_back(0, a);
+    }
+    for (int a, b, c; M--; V[a].emplace_back(b, c), V[b].emplace_back(a, c)) cin >> a >> b >> c;
+
+    while (!PQ.empty()) {
+        auto [d, p, n] = PQ.top();    PQ.pop();
+        bool con = false, ex = false;
+        for (auto [_, q] : D[n]) {
+            if (q == p) {
+                ex = 1;
+                if (d > _) con = 1;
+            }
+        }
+        if (!ex) con = 1;
+        if (con) continue;
+        for (auto [i, c] : V[n]) {
+            int org = -1;
+            for (auto [_, q] : D[i]) {
+                if (p == q) org = _;
+            }
+            stack<pair<int, int>> tmp;
+            if (org == -1) {
+                while (!D[i].empty() && D[i].back().first > d+c) {
+                    tmp.push(D[i].back());
+                    D[i].pop_back();
+                }
+                if (D[i].size() < 11) {
+                    D[i].emplace_back(d + c, p);
+                    PQ.emplace(d + c, p, i);
+                }
+                while (D[i].size() < 11 && !tmp.empty()) {
+                    D[i].emplace_back(tmp.top());
+                    tmp.pop();
+                }
+            }
+            else if (d + c < org) {
+                while (!D[i].empty() && D[i].back().first > d+c) {
+                    if(D[i].back().second != p) tmp.push(D[i].back());
+                    D[i].pop_back();
+                }
+                D[i].emplace_back(d + c, p);
+                while (!tmp.empty()) {
+                    D[i].emplace_back(tmp.top());
+                    tmp.pop();
+                }
+                PQ.emplace(d + c, p, i);
+            }
+        }
+    }
+
+    for (int s, c, a; Q--;) {
+        vector<int> t;
+        for (cin >> s >> c; c--; t.push_back(a)) cin >> a;
+        bool pr = false;
+        for (int i = 0; i < D[s].size(); i++) {
+            bool cant = false;
+            for (int j : t) cant |= j == D[s][i].second;
+            if (!cant) {
+                pr = true;
+                cout << D[s][i].second << ' ' << D[s][i].first << '\n';
+                break;
+            }
+        }
+    }
+
+}
+```