Box Stack II

#include <bits/stdc++.h>
using namespace std;

struct Box {
    int x;
    int y;
    long long z;
    int y_rank;
};

struct FenwickTree {
    int size;
    vector<long long> tree;

    FenwickTree(int n) : size(n), tree(n + 1, 0) {}

    void update(int idx, long long val) {
        while (idx <= size) {
            if (val > tree[idx]) {
                tree[idx] = val;
            } else {
                break;
            }
            idx += idx & (-idx);
        }
    }

    long long query(int idx) const {
        long long res = 0;
        int current = idx;
        while (current > 0) {
            res = max(res, tree[current]);
            current -= current & (-current);
        }
        return res;
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int n;
    cin >> n;
    vector<Box> boxes(n);
    vector<int> ys(n);
    for(int i=0; i < n; ++i){
        cin >> boxes[i].x >> boxes[i].y >> boxes[i].z;
        ys[i] = boxes[i].y;
    }

    sort(boxes.begin(), boxes.end(), [&](const Box &a, const Box &b) -> bool {
        if(a.x != b.x) return a.x < b.x;
        return a.y < b.y;
    });

    vector<int> sorted_ys = ys;
    sort(sorted_ys.begin(), sorted_ys.end());
    sorted_ys.erase(unique(sorted_ys.begin(), sorted_ys.end()), sorted_ys.end());

    for(int i=0; i < n; ++i){
        boxes[i].y_rank = lower_bound(sorted_ys.begin(), sorted_ys.end(), boxes[i].y) - sorted_ys.begin() + 1;
    }

    int m = sorted_ys.size();
    FenwickTree BIT(m);

    long long global_max = 0;

    for(int i=0; i < n; ++i){
        int y_r = boxes[i].y_rank;
        long long current_max = BIT.query(y_r);
        long long dp = current_max + boxes[i].z;
        global_max = max(global_max, dp);
        BIT.update(y_r, dp);
    }

    cout << global_max;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

Verdict: ACCEPTED

Test 58

Verdict: ACCEPTED

Test 59

Verdict: ACCEPTED

Test 60

Verdict: ACCEPTED

Test 61

Verdict: ACCEPTED

Test 62

Verdict: ACCEPTED

Test 63

Verdict: ACCEPTED

Test 64

Verdict: ACCEPTED

Test 65

Verdict: ACCEPTED

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: ACCEPTED

Test 69

Verdict: ACCEPTED

Test 70

Verdict: ACCEPTED

Test 71

Verdict: ACCEPTED

Test 72

Verdict: ACCEPTED

Test 73

Verdict: ACCEPTED