202012

.vscode/settings.json

@@ -1,6 +1,7 @@
 {
     "files.associations": {
         "iostream": "cpp",
-        "ostream": "cpp"
+        "ostream": "cpp",
+        "cstring": "cpp"
     }
 }

202012/1.cpp

@@ -0,0 +1,25 @@
+#include <iostream>
+#include <cstring>
+#include <algorithm>
+
+using namespace std;
+
+int n;
+
+int main() {
+    cin >> n;
+
+    int sum = 0;
+
+    for (int i = 1; i <= n; i++) {
+        int w, score;
+        cin >> w >> score;
+
+        sum += w * score;
+    }
+
+    if (sum > 0) cout << sum << endl;
+    else cout << "0" << endl;
+
+    return 0;
+}

202012/2.cpp

@@ -0,0 +1,68 @@
+#include <iostream>
+#include <cstring>
+#include <algorithm>
+#include <map>
+
+#define x first
+#define y second
+
+using namespace std;
+
+typedef pair<int, int> pii;
+int m;
+pii p[100010];
+int les[100010];
+int more[100010];
+map<int, int> mp;
+map<int, pii> info;
+int thres[100010];
+
+int main() {
+    cin >> m;
+
+    for (int i = 1; i <= m; i++) {
+        int thre, result;
+        cin >> thre >> result;
+        p[i] = {thre, result};
+        mp[thre] ++;
+        if (result == 0) info[thre].x ++;
+        else info[thre].y ++;
+    }
+
+    sort(p + 1, p + m + 1);
+
+    int n = 1;
+    for (int i = 1; i <= m; i++) {
+        if (i == 1) thres[n ++] = p[i].x;
+        else {
+            if (p[i].x == p[i - 1].x) continue;
+            else thres[n ++] = p[i].x;
+        }
+    }
+
+    n --;
+    int cnt = 0;
+    for (int i = 2; i <= n; i++) {
+        cnt += info[thres[i - 1]].x;
+        les[i] = cnt;
+    }
+
+    cnt = 0;
+    for (int i = n; i >= 1; i--) {
+        cnt += info[thres[i]].y;
+        more[i] = cnt;
+    }
+
+    int sum = 0, ans;
+    for (int i = 1; i <= n; i++) {
+        int cur = les[i] + more[i];
+        // cout << i << " : " << les[i] << " " << more[i] << endl;
+        if (cur >= sum) {
+            sum = cur;
+            ans = thres[i];
+        }
+    }
+
+    cout << ans << endl;
+    return 0;
+}

202012/3.cpp

@@ -0,0 +1,166 @@
+// cv
+#include <iostream>
+#include <cstring>
+#include <algorithm>
+#include <vector>
+#include <set>
+
+using namespace std;
+
+typedef long long LL;
+const int N = 2000010;
+
+int n;
+struct Node {
+    string name;
+    int id, type;  // type == 0: 文件夹；type == 1：文件
+    mutable LL ld, lr;
+    mutable LL sd, sr;
+    bool operator< (const Node& t) const {
+        return name < t.name;
+    }
+};
+set<Node> son[N];
+int idx;
+char str[N];
+bool F;
+int U;
+LL SZ;
+
+vector<string> get(char* str) {
+    vector<string> res(1, "root");
+    for (int i = 0; str[i]; i ++ ) {
+        if (str[i] == '/') continue;
+        string s;
+        int j = i;
+        while (str[j] && str[j] != '/') s += str[j ++ ];
+        res.push_back(s);
+        i = j - 1;
+    }
+
+    return res;
+}
+
+LL dfs_remove(vector<string>& t, int u, int p) {
+    string name = t[u];
+    if (!son[p].count({name})) return -1;
+    auto it = son[p].find({name});
+    if (u == t.size() - 1) {
+        if (it->type) t[u] = "#file";
+        auto sz = it->sr;
+        son[p].erase(it);
+        return sz;
+    }
+    if (it->type) return -1;
+    auto sz = dfs_remove(t, u + 1, it->id);
+    if (sz >= 0) {
+        it->sr -= sz;
+        if (t[u + 1] == "#file") it->sd -= sz;
+    }
+    return sz;
+}
+
+bool dfs_create(vector<string>& t, int u, int p, LL sz) {
+    string name = t[u];
+    if (u == t.size() - 1) {
+        if (son[p].count({name})) {
+            auto it = son[p].find({name});
+            if (it->type == 0) return false;
+            SZ = dfs_remove(t, 0, 0);
+            Node cur{name, ++ idx, 1, 0, 0, 0, sz};
+            son[p].insert(cur);
+            return true;
+        }
+        else {
+            Node cur{name, ++ idx, 1, 0, 0, 0, sz};
+            son[p].insert(cur);
+            return true;
+        }
+    }
+    else {
+        if (!son[p].count({name})) {
+            if (U == -1) U = u;
+            Node cur{name, ++ idx, 0, 0, 0, 0, 0};
+            son[p].insert(cur);
+        }
+
+        auto it = son[p].find({name});
+        if (it->type) return false;
+        auto res = dfs_create(t, u + 1, it->id, sz);
+        if (res) {
+            it->sr += sz;
+            if (u + 1 == t.size() - 1) it->sd += sz;
+
+            if (it->lr && it->sr > it->lr) F = false;
+            if (it->ld && it->sd > it->ld) F = false;
+        }
+        return res;
+    }
+}
+
+bool create(char* str, LL sz) {
+    auto t = get(str);
+    F = true, U = -1, SZ = -1;
+    auto res = dfs_create(t, 0, 0, sz);
+
+    auto ans = res && F;
+    if (res && !F) {
+        auto t = get(str);
+        if (U != -1) {
+            while (t.size() - 1 > U) t.pop_back();
+        }
+        dfs_remove(t, 0, 0);
+        if (SZ != -1) create(str, SZ);
+    }
+    return ans;
+}
+
+bool update(char* str, LL d, LL r) {
+    auto t = get(str);
+    int p = 0;
+    for (int i = 0; i < t.size(); i ++ ) {
+        string& s = t[i];
+        auto it = son[p].find({s});
+        if (it == son[p].end()) return false;
+        if (it->type) return false;
+        if (i == t.size() - 1) {
+            if (d && d < it->sd) return false;
+            if (r && r < it->sr) return false;
+            it->ld = d, it->lr = r;
+        }
+        p = it->id;
+    }
+    return true;
+}
+
+int main() {
+    scanf("%d", &n);
+    char op[2];
+    sprintf(str, "/tmp");
+    create(str, 1);
+    auto t = get(str);
+    dfs_remove(t, 0, 0);
+    while (n -- ) {
+        scanf("%s", op);
+        bool res;
+        if (*op == 'C') {
+            LL sz;
+            scanf("%s%lld", str, &sz);
+            res = create(str, sz);
+        }
+        else if (*op == 'R') {
+            scanf("%s", str);
+            auto t = get(str);
+            dfs_remove(t, 0, 0);
+            res = true;
+        }
+        else {
+            LL d, r;
+            scanf("%s%lld%lld", str, &d, &r);
+            res = update(str, d, r);
+        }
+        if (res) puts("Y");
+        else puts("N");
+    }
+    return 0;
+}

202012/4.cpp

@@ -0,0 +1,79 @@
+#include <iostream>
+#include <cstring>
+#include <algorithm>
+
+#define x first
+#define y second
+
+using namespace std;
+
+typedef pair<int, int> PII;
+const int N = 110, M = 10, S = 1 << M;
+
+int n, m, k;
+int need[N][M];
+int h[N], e[N * 2], w[N * 2], ne[N * 2], idx;
+int d[N][M];
+int f[S], state[N];
+
+void add(int a, int b, int c) {
+    e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx ++ ;
+}
+
+PII dfs(int u, int fa, int v) {
+    PII res(0, -1);
+    if (need[u][v]) res.y = 0;
+    for (int i = h[u]; ~i; i = ne[i]) {
+        int j = e[i];
+        if (j == fa) continue;
+        auto t = dfs(j, u, v);
+        if (t.y != -1) {
+            res.x += t.x + w[i] * 2;
+            res.y = max(res.y, t.y + w[i]);
+        }
+    }
+    return res;
+}
+
+bool check(int mid) {
+    memset(state, 0, sizeof state);
+    for (int i = 1; i <= n; i ++ )
+        for (int j = 0; j < k; j ++ )
+            if (d[i][j] <= mid)
+                state[i] |= 1 << j;
+    memset(f, 0x3f, sizeof f);
+    f[0] = 0;
+    for (int i = 0; i < 1 << k; i ++ )
+        for (int j = 1; j <= n; j ++ )
+            f[i | state[j]] = min(f[i | state[j]], f[i] + 1);
+    return f[(1 << k) - 1] <= m;
+}
+
+int main() {
+    cin >> n >> m >> k;
+    for (int i = 1; i <= n; i ++ )
+        for (int j = 0; j < k; j ++ )
+            cin >> need[i][j];
+    memset(h, -1, sizeof h);
+    for (int i = 0; i < n - 1; i ++ ) {
+        int a, b, c;
+        scanf("%d%d%d", &a, &b, &c);
+        add(a, b, c), add(b, a, c);
+    }
+
+    for (int i = 1; i <= n; i ++ )
+        for (int j = 0; j < k; j ++ ) {
+            auto t = dfs(i, -1, j);
+            if (t.y != -1) d[i][j] = t.x - t.y;
+        }
+
+    int l = 0, r = 2e8;
+    while (l < r) {
+        int mid = l + r >> 1;
+        if (check(mid)) r = mid;
+        else l = mid + 1;
+    }
+
+    printf("%d\n", r);
+    return 0;
+}