Some easy problems from HDOJ

Author: Macesuted

.gitignore

@@ -1,3 +1,6 @@
 tools/testlib.h
 tools/linux/check
-tools/windows/check.exe
+tools/windows/check.exe
+
+_work
+_work/*

.vscode/extensions.json

@@ -0,0 +1,10 @@
+{
+    "recommendations": [
+        "aaron-bond.better-comments",
+        "coenraads.bracket-pair-colorizer-2",
+        "ms-vscode.cpptools",
+        "formulahendry.code-runner",
+        "cschlosser.doxdocgen",
+        "icrawl.discord-vscode"
+    ]
+}

.vscode/settings.json

@@ -13,4 +13,19 @@
   "code-runner.ignoreSelection": true,
   "C_Cpp.clang_format_sortIncludes": true,
   "C_Cpp.clang_format_fallbackStyle": "{BasedOnStyle: Google, UseTab: Never, IndentWidth: 4, TabWidth: 4, UseTab: Never, ColumnLimit: 0}",
+  "files.autoSave": "onFocusChange",
+  "editor.cursorSmoothCaretAnimation": true,
+  "editor.smoothScrolling": true,
+  "workbench.list.smoothScrolling": true,
+  "editor.fontFamily": "Fira Code",
+  "editor.fontLigatures": true,
+  "editor.fontWeight": "600",
+  "files.associations": {
+    "chrono": "cpp",
+    "random": "cpp",
+    "limits": "cpp",
+    "valarray": "cpp",
+    "ostream": "cpp",
+    "cmath": "cpp"
+  }
 }

HDOJ/6954.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool mem1;
+
+#define maxn 10000005
+#define mod 998244353
+
+vector<int> prime;
+bool vis[maxn];
+
+void init(void) {
+    for (int i = 2; i < maxn; i++) {
+        if (!vis[i]) prime.push_back(i);
+        for (auto j : prime) {
+            if (i * j >= maxn) break;
+            vis[i * j] = true;
+            if (i % j == 0) break;
+        }
+    }
+    return;
+}
+void solve(void) {
+    long long n, ans = 0;
+    cin >> n;
+    for (int i = 3; i <= n; i++) ans += i * (1 + !vis[i]);
+    cout << ans << endl;
+    return;
+}
+
+bool mem2;
+
+signed main() {
+    ios::sync_with_stdio(false);
+    init();
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+    return 0;
+}

HDOJ/6968.cpp

@@ -0,0 +1,76 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool mem1;
+
+#define maxn 55
+#define maxt 505
+#define maxm 15005
+
+typedef pair<int, int> pii;
+
+long long f[maxn][maxt][4], g[maxt];
+
+map<string, int> rec;
+vector<pii> a[maxn];
+int cnt = 0;
+
+void solve(void) {
+    int n;
+    cin >> n;
+    rec.clear(), cnt = 0;
+    for (int i = 1; i <= n; i++) a[i].clear();
+    for (int i = 1; i <= n; i++) {
+        string s;
+        cin >> s;
+        rec[s] = ++cnt;
+    }
+    int m;
+    cin >> m;
+    for (int i = 1; i <= m; i++) {
+        string s;
+        cin >> s;
+        int p = rec[s], x, y;
+        cin >> x >> y;
+        a[p].emplace_back(y, x);
+    }
+    int T, P;
+    cin >> T >> P;
+    for (int i = 1; i <= n; i++)
+        for (int j = 0; j <= T; j++)
+            for (int k = 0; k <= P; k++)
+                f[i][j][k] = numeric_limits<int>::min() / 2;
+    f[0][0][0] = 0;
+    for (int i = 1; i <= n; i++) {
+        for (int k = 0; k <= T; k++) g[k] = numeric_limits<int>::min() / 2;
+        g[0] = 0;
+        for (auto j : a[i])
+            for (int k = T; k >= j.first; k--)
+                g[k] = max(g[k], g[k - j.first] + j.second);
+        for (int k = 0; k <= T; k++) g[k] = min(g[k], 100LL);
+        for (int k = 0; k <= T; k++)
+            for (int j = T; j >= k; j--)
+                for (int t = 0; t <= P; t++) {
+                    if (t == 0 && g[k] < 60) continue;
+                    f[i][j][t] = max(f[i][j][t], f[i - 1][j - k][t - (g[k] < 60)] + g[k]);
+                }
+    }
+    int ans = numeric_limits<int>::min();
+    for (int j = 0; j <= T; j++)
+        for (int k = 0; k <= P; k++)
+            ans = max(ans, f[n][j][k]);
+    cout << max(-1LL, ans) << endl;
+    return;
+}
+
+bool mem2;
+
+signed main() {
+    ios::sync_with_stdio(false);
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+    return 0;
+}

HDOJ/6983.cpp

@@ -0,0 +1,33 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool mem1;
+
+map<int, int> S;
+int n, k;
+
+int dfs(int p) {
+    if (p <= k) return 1;
+    if (S.find(p) != S.end()) return S[p];
+    int mid = p >> 1;
+    return S[p] = 1 + dfs(mid) + dfs(p - mid);
+}
+
+void solve(void) {
+    cin >> n >> k;
+    cout << dfs(n) << endl;
+    S.clear();
+    return;
+}
+
+bool mem2;
+
+signed main() {
+    ios::sync_with_stdio(false);
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+    return 0;
+}

HDOJ/6986.cpp

@@ -0,0 +1,62 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool mem1;
+
+#define maxn 2005
+#define mod1 1000000007
+#define mod2 1000000009
+#define base 19560929
+
+vector<vector<int>> graph;
+
+int c[maxn], f[maxn];
+int cnt[maxn], cntt = 0;
+
+void dfs(int p, int pre = -1) {
+    if (cnt[c[p]] == 0) cntt++;
+    cnt[c[p]]++;
+    f[p] = cntt;
+    for (auto i : graph[p])
+        if (i != pre) dfs(i, p);
+    cnt[c[p]]--;
+    if (cnt[c[p]] == 0) cntt--;
+    return;
+}
+
+void solve(void) {
+    int n;
+    cin >> n;
+    graph.resize(n + 1);
+    for (int i = 2; i <= n; i++) {
+        int f;
+        cin >> f;
+        graph[f].push_back(i), graph[i].push_back(f);
+    }
+    for (int i = 1; i <= n; i++) cin >> c[i];
+    for (int i = 1; i <= n; i++) {
+        dfs(i);
+        int ans = 0, p = 1;
+        for (int j = 1; j <= n; j++)
+            ans = (ans + p * f[j]) % mod1, p = p * base % mod1;
+        cout << ans << ' ';
+        ans = 0, p = 1;
+        for (int j = 1; j <= n; j++)
+            ans = (ans + p * f[j]) % mod2, p = p * base % mod2;
+        cout << ans << endl;
+    }
+    graph.clear();
+    return;
+}
+
+bool mem2;
+
+signed main() {
+    ios::sync_with_stdio(false);
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+    return 0;
+}

HDOJ/7055.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool mem1;
+
+#define maxn 100005
+#define mod 998244353
+
+string s;
+
+vector<int> pos[26];
+
+void solve(void) {
+    cin >> s;
+    int n = s.size();
+    s = ' ' + s;
+    for (int i = 1; i <= n; i++) pos[s[i] - 'a'].push_back(i);
+    long long answer = 0;
+    for (int t = 0; t < 26; t++) {
+        long long sum = 0;
+        for (auto i : pos[t]) sum += n - i + 1;
+        for (auto i : pos[t])
+            sum -= n - i + 1, answer = (answer + i * sum * 2 + i * (n - i + 1)) % mod;
+        pos[t].clear();
+    }
+    cout << answer << endl;
+    return;
+}
+
+bool mem2;
+
+signed main() {
+    ios::sync_with_stdio(false);
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+    return 0;
+}

HDOJ/7058.cpp

@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define int long long
+
+bool mem1;
+
+#define maxn 5005
+#define mod 998244353
+
+typedef pair<int, int> pii;
+
+pii a[maxn];
+int dist[maxn];
+bool vis[maxn];
+
+inline long long Dist(pii a, pii b) {
+    return (a.first - b.first) * (a.first - b.first) + (a.second - b.second) * (a.second - b.second);
+}
+
+void solve(void) {
+    int n;
+    cin >> n;
+    for (int i = 1; i <= n; i++) cin >> a[i].first >> a[i].second;
+    memset(dist, 0x3f, sizeof(dist));
+    memset(vis, false, sizeof(vis));
+    dist[1] = 0;
+    int ans = 0;
+    while (true) {
+        int p = 0;
+        for (int i = 1; i <= n; i++)
+            if ((!vis[i]) && ((p == 0) || (dist[i] < dist[p])))
+                p = i;
+        if (p == 0) break;
+        vis[p] = true;
+        ans = max(ans, dist[p]);
+        for (int i = 1; i <= n; i++)
+            if ((!vis[i]) && dist[i] > Dist(a[p], a[i]))
+                dist[i] = Dist(a[p], a[i]);
+    }
+    cout << ans << endl;
+    return;
+}
+
+bool mem2;
+
+signed main() {
+    ios::sync_with_stdio(false);
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+    return 0;
+}