Add Projects problem

Okay, this one was tough, segtree with dp? At least it's pretty similar
to LIS with dp...

CSES Problem Set/Projects.cpp

@@ -0,0 +1,160 @@
+/* Problem URL: https://cses.fi/problemset/task/1140 */
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define V vector
+
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+
+#define rep(i, lim) for (size_t i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (size_t i = s; i < (lim); i++)
+
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+
+using ll = long long;
+
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+
+class segtree {
+    vl seg;
+
+    ll _query(int i, int l, int r, int ql, int qr) {
+        if (l > qr || r < ql) {
+            return -1;
+        }
+
+        if (l >= ql && r <= qr) {
+            return seg[i];
+        }
+
+        int mid = (l + r) / 2;
+        return max(_query(i * 2, l, mid, ql, qr), _query(i * 2 + 1, mid + 1, r, ql, qr));
+    }
+
+    public:
+    segtree() = delete;
+    segtree(vl &items): seg(items.size() * 2) {
+        size_t n = items.size();
+        for (size_t i = n; i < n * 2; i++) {
+            seg[i] = items[i - n];
+        }
+
+        for (size_t i = n - 1; i > 0; i--) {
+            seg[i] = max(seg[i * 2], seg[i * 2 + 1]);
+        }
+    }
+
+    void update(ll v, int i) {
+        i += seg.size() / 2;
+        if (seg[i] >= v) {
+            return;
+        }
+        seg[i] = v;
+        i /= 2;
+        for (; i > 0; i /= 2) {
+            seg[i] = max(seg[i * 2], seg[i * 2 + 1]);
+        }
+    }
+
+    ll query(int i) {
+        return _query(1, 0, seg.size() / 2 - 1, 0, i);
+    }
+};
+
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n;
+    cin >> n;
+    V<tuple<ll, ll, ll>> fds(n);
+    set<ll> lol;
+    for (auto &[i, e, v] : fds) {
+        cin >> i >> e >> v;
+        lol.insert(e);
+    }
+
+    pair<vl, vl> ends(vl(lol.size(), 0), vl(lol.size()));
+    auto itr = lol.begin();
+    for (size_t i = 0; itr != lol.end(); i++, itr++) {
+        ends.second[i] = *itr;
+    }
+
+    sort(fds.begin(), fds.end());
+
+    ll neutral = 1e9 + 1;
+    while (__builtin_popcount(ends.second.size()) != 1) {
+        ends.first.push_back(-1);
+        ends.second.push_back(neutral++);
+    }
+
+    segtree seg(ends.first);
+
+    for (auto [i, f, v] : fds) {
+        auto itr = lower_bound(ends.second.begin(), ends.second.end(), i);
+        if (itr == ends.second.begin()) {
+            seg.update(v, lower_bound(ends.second.begin(), ends.second.end(), f) - ends.second.begin());
+            continue;
+        }
+
+        ll up = seg.query(itr - ends.second.begin() - 1) + v;
+        seg.update(up, lower_bound(ends.second.begin(), ends.second.end(), f) - ends.second.begin());
+    }
+
+    cout << seg.query(ends.first.size() - 1) << '\n';
+}