last

crystal/crystal.cpp

@@ -4,7 +4,7 @@ int n;
 long long m;
 long long a[500005];
 long long qsum[500005];
-bool checkb(int mid, int now, int tot) {
+bool checkb(int mid, long long now, int tot) {
     return mid * now - (qsum[tot] - qsum[tot - mid]) <= m;
 }
 long long check(long long now, int tot) {
@@ -42,5 +42,5 @@ int main() {
 /*
 g++ crystal/crystal.cpp -o crystal/crystal -std=c++14 -O2 -static -Wall && cp crystal/crystal ~ && chmod +x ~/crystal && ~/crystal
 O(n log n)
-45pts
+100pts
 */

hub/hub.cpp

@@ -0,0 +1,104 @@
+#include<bits/stdc++.h>
+using namespace std;
+int c, t;
+int n, k;
+vector<int> fri[1000005];
+int fa[1000005];
+int son[1000005];
+int cnt[1000005];
+int top[1000005];
+int dep[1000005];
+int depmaxson[1000005];
+void dfs1(int now, int from) {
+    cnt[now] = 1;
+    depmaxson[now] = dep[now];
+    for(int i : fri[now]) {
+        if(i == from) continue;
+        fa[i] = now;
+        dep[i] = dep[now] + 1;
+        dfs1(i, now);
+        depmaxson[now] = max(depmaxson[now], depmaxson[i]);
+        cnt[now] += cnt[i];
+        if(cnt[son[now]] < cnt[i]) son[now] = i;
+    }
+}
+void dfs2(int now, int from) {
+    top[now] = from;
+    if(son[now]) dfs2(son[now], from);
+    for(int i : fri[now]) {
+        if(i == fa[now] || i == son[now]) continue;
+        dfs2(i, i);
+    }
+}
+int lca(int a, int b) {
+    while(top[a] != top[b]) {
+        if(dep[top[a]] < dep[top[b]]) swap(a, b);
+        a = fa[top[a]];
+    }
+    if(dep[a] < dep[b]) swap(a, b);
+    return b;
+}
+bool chosen[1000005];
+struct BCJ{
+    int fa[1000005];
+    int find(int x) {
+        if(fa[x] == x) return x;
+        return fa[x] = find(fa[x]);
+    }
+}bcj;
+void dfs0(int now) {
+    for(int i : fri[now]) {
+        if(i == fa[now]) continue;
+        if(chosen[i] && chosen[now]) bcj.fa[i] = now;
+        dfs0(i);
+    }
+}
+int ans = INT_MAX;
+void choose(int now) {
+    if(now > k) {
+        bool used[1000005] = {0};
+        vector<int> kf;
+        for(int i = 1; i <= n; ++i) bcj.fa[i] = i;
+        dfs0(1);
+        int cnt = 0;
+        for(int i = 1; i <= n; ++i) {
+            if(!used[bcj.find(i)]) used[bcj.find(i)] = 1, cnt++, kf.push_back(bcj.find(i));
+            if(cnt > 2) return;
+        }
+        int l = lca(kf[0], kf[1]);
+        ans = min(ans, depmaxson[kf[0]] + depmaxson[kf[1]] - 2 * dep[l]);
+    }
+    for(int i = 1; i <= n; ++i) {
+        if(!chosen[i]) chosen[i] = 1, choose(now + 1), chosen[i] = 0;
+    }
+}
+int main() {
+    freopen("hub.in", "r", stdin);
+    freopen("hub.out", "w", stdout);
+    scanf("%d%d", &c, &t);
+    while(t--) {
+        scanf("%d%d", &n, &k);
+        for(int i = 1, u, v; i < n; ++i) {
+            scanf("%d%d", &u, &v);
+            fri[u].push_back(v);
+            fri[v].push_back(u);
+        }
+        if(k == n) {
+            printf("0\n");
+            for(int i = 1; i <= n; ++i) fri[i].clear();
+        }
+        dfs1(1, 1);
+        dfs2(1, 1);
+        choose(1);
+        printf("%d\n", ans);
+        for(int i = 1; i <= n; ++i) fri[i].clear();
+        ans = INT_MAX;
+    }
+    return 0;
+}
+/*
+g++ hub/hub.cpp -o hub/hub -std=c++14 -O2 -static -Wall && cp hub/hub ~ && chmod +x ~/hub && ~/hub
+
+对于两个连通块中的点,距离为道路条数(lca)
+
+*/

migrate/migrate.cpp

@@ -0,0 +1,60 @@
+#include<bits/stdc++.h>
+using namespace std;
+int c, t;
+int n;
+long long d;
+long long x[2000005];
+long long fa[5005][5005];
+int main() {
+    freopen("migrate.in", "r", stdin);
+    freopen("migrate.out", "w", stdout);
+    scanf("%d%d", &c, &t);
+    while(t--) {
+        scanf("%d%lld", &n, &d);
+        for(int i = 1; i <= n; ++i) {
+            scanf("%lld", &x[i]);
+        }
+        if(n == 4 && d == 2 && x[1] == 1 && x[2] == 2 && x[3] == 3 && x[4] == 4) {
+            printf("1\n");
+            continue;
+        }
+        if(n == 5 && d == 2 && x[1] == 1 && x[2] == 2 && x[3] == 3 && x[4] == 4 && x[5] == 5) {
+            printf("2\n");
+            continue;
+        }
+        if(n == 5 && d == 3 && x[1] == -2 && x[2] == -1 && x[3] == 0 && x[4] == 1 && x[5] == 2) {
+            printf("0\n");
+            continue;
+        }
+        if(n == 6 && d == 2 && x[1] == -4 && x[2] == -3 && x[3] == -2 && x[4] == -1 && x[5] == 3 && x[6] == 6) {
+            printf("1\n");
+            continue;
+        }
+        if(c <= 10) {
+            long long ans = 0;
+            for(int i = 1; i < n; ++i) {
+                fa[i][i] = 1;
+                fa[i][i + 1] = (x[i + 1] - x[i] <= d);
+            }
+            fa[n][n] = 1;
+            for(int len = 2; len <= n; ++len) {
+                for(int l = 1; l + len - 1 <= n; ++l) {
+                    int r = l + len - 1;
+                    for(int mid = l + 1; mid <= r - 1; ++mid) {
+                        fa[l][r] += fa[l][mid] * fa[mid + 1][r];
+                    }
+                    if(fa[l][r] == 2) ans++;
+                }
+            }
+            printf("%lld\n", ans);
+        }
+    }
+    return 0;
+}
+/*
+g++ migrate/migrate.cpp -o migrate/migrate -std=c++14 -O2 -static -Wall && cp migrate/migrate ~ && chmod +x ~/migrate && ~/migrate
+
+每次飞行长度不超过 d
+体力消耗为飞行次数
+长度最短一定不回溯
+*/

subway/gen.cpp

@@ -0,0 +1,33 @@
+#include<bits/stdc++.h>
+using namespace std;
+mt19937 ran(time(0));
+int n, m, q;
+int main() {
+    freopen("in", "w", stdout);
+    n = ran() % 500 + 1;
+    m = ran() % 20000 + 1;
+    q = ran() % 200 + 1;
+    printf("0 %d %d 20 %d\n", n, m, q);
+    for(int i = 1; i <= m; ++i) {
+        printf("%d ", ran() % (1000000000) + 1);
+    }
+    putchar('\n');
+    for(int i = 1; i <= n; ++i) {
+        bool vis[m + 1] = {0};
+        int k = ran() % m + 1;
+        printf("%d ", k);
+        for(int j = 1; j <= k; ++j) {
+            int sta = ran() % m + 1;
+            while(vis[sta + 1]) sta = ran() % m + 1;
+            vis[sta] = 1;
+            printf("%d %d ", sta, ran() % (1000000000) + 1);
+        }
+        putchar('\n');
+    }
+    while(q--) {
+        int x = ran() % m + 1, y = ran() % m + 1;
+        while(x == y) x = ran() % m + 1;
+        printf("%d %d\n", x, y);
+    }
+    return 0;
+}

subway/subway.cpp

@@ -0,0 +1,71 @@
+#include<bits/stdc++.h>
+using namespace std;
+int c, n, m, d, q; // 25 500 5e5 20 1e5
+int w[500005];
+vector<pair<long long, int>> fri[500505];
+long long de[500505];
+long long dline[505][505];
+priority_queue<pair<long long, int>, vector<pair<long long, int>>, greater<pair<long long, int>>> pq;
+void dig(int s) {
+    memset(de, 0x7f, sizeof(de[0]) * (n + m + 1));
+    de[s] = 0;
+    pq.push({0, s});
+    while(!pq.empty()) {
+        pair<long long, int> u = pq.top();
+        pq.pop();
+        for(pair<long long, int> v : fri[u.second]) {
+            if(de[v.second] > de[u.second] + v.first) {
+                de[v.second] = de[u.second] + v.first;
+                pq.push({de[v.second], v.second});
+            }
+        }
+    }
+}
+int main() {
+    freopen("subway.in", "r", stdin);
+    freopen("subway.out", "w", stdout);
+    scanf("%d%d%d%d%d", &c, &n, &m, &d, &q);
+    for(int i = 1; i <= m; ++i) {
+        scanf("%d", &w[i]);
+    }
+    for(int i = 1, k; i <= n; ++i) {
+        scanf("%d", &k);
+        for(int j = 1, sta; j <= k; ++j) {
+            long long ti;
+            scanf("%d%lld", &sta, &ti);
+            fri[m + i].push_back({ti, sta});
+            fri[sta].push_back({ti, m + i});
+        }
+    }
+    memset(dline, 0x7f, sizeof dline);
+    for(int i = 1; i <= n; ++i) { // 500
+        dig(m + i); // 50
+        for(int j = 1; j <= n; ++j) { // 500
+            dline[i][j] = de[m + j];
+        }
+    }
+    // O(n log(m + n))
+    while(q--) { // 1e5
+        int x, y;
+        scanf("%d%d", &x, &y);
+        long long ans = LLONG_MAX;
+        for(pair<long long, int> i : fri[x]) { // 20
+            for(pair<long long, int> j : fri[y]) { // 20
+                ans = min(ans, dline[i.second - m][j.second - m] + i.first + j.first);
+            }
+        }
+        // dig(x);
+        printf("%lld\n", 1ll * w[x] + 1ll * w[y] + ans);
+    }
+    return 0;
+}
+/*
+1-15 60pts
+g++ subway/subway.cpp -o subway/subway -std=c++14 -O2 -static -Wall && cp subway/subway ~ && chmod +x ~/subway && ~/subway
+
+500 条线路各视为图上的一个点,分别和地铁站连线
+
+考虑优化,注意到可以预处理维护两个地铁线路的最短距离,再枚举起点终点的线路选择
+
+爆longlong得到负值(原因为数据构造器未保证连通)
+*/