Submission #627635

#	Time	Username	Problem	Language	Result	Execution time	Memory
627635		dqhungdl	Catfish Farm (IOI22_fish)	C++17	100 / 100	464 ms	73464 KiB

fish

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

typedef pair<int, int> ii;
const int MAX = 1e5 + 5, SINF = 2e9;
const long long INF = 1e18;
bool markLow[MAX];
vector<ii> g[MAX];
vector<long long> S[MAX];
vector<vector<long long>> f[MAX];

struct FenwickTreeLow {
    int n;
    vector<int> buffer;
    vector<long long> tree;

    FenwickTreeLow(int _n) {
        n = _n;
        tree.resize(n + 5, -INF);
    }

    void update(int idx, long long val) {
        idx++;
        for (int i = idx; i <= n; i += i & -i) {
            buffer.push_back(i);
            tree[i] = max(tree[i], val);
        }
    }

    long long get(int idx) {
        idx++;
        long long rs = 0;
        for (int i = idx; i > 0; i -= i & -i)
            rs = max(rs, tree[i]);
        return rs;
    }

    void reset() {
        for (int id: buffer)
            tree[id] = -INF;
        buffer.clear();
    }
};

struct FenwickTreeHigh {
    int n;
    vector<int> buffer;
    vector<long long> tree;

    FenwickTreeHigh(int _n) {
        n = _n;
        tree.resize(n + 5, -INF);
    }

    void update(int idx, long long val) {
        idx++;
        for (int i = idx; i > 0; i -= i & -i) {
            buffer.push_back(i);
            tree[i] = max(tree[i], val);
        }
    }

    long long get(int idx) {
        idx++;
        long long rs = 0;
        for (int i = idx; i <= n; i += i & -i)
            rs = max(rs, tree[i]);
        return rs;
    }

    void reset() {
        for (int id: buffer)
            tree[id] = -INF;
        buffer.clear();
    }
};

long long calcCostLeft(int col, int L) {
    int l = lower_bound(g[col].begin(), g[col].end(), ii(L, 0)) - g[col].begin();
    return l ? S[col][l - 1] : 0;
}

long long calcCostRight(int col, int R) {
    int r = upper_bound(g[col].begin(), g[col].end(), ii(R, 0)) - g[col].begin() - 1;
    return r >= 0 ? S[col][r] : 0;
}

long long max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    for (int i = 0; i < M; i++) {
        g[X[i]].emplace_back(Y[i], W[i]);
        if (!Y[i])
            markLow[X[i]] = true;
    }
    for (int i = 0; i < N; i++) {
        if (!markLow[i])
            g[i].emplace_back(0, 0);
        g[i].emplace_back(N, 0);
    }
    for (int i = 0; i < N; i++) {
        sort(g[i].begin(), g[i].end());
        S[i].resize(g[i].size());
        S[i][0] = g[i][0].second;
        for (int j = 1; j < g[i].size(); j++)
            S[i][j] = S[i][j - 1] + g[i][j].second;
        f[i].resize(g[i].size(), vector<long long>(2));
    }
    FenwickTreeLow lowTree(N + 5), lowJump(N + 5);
    FenwickTreeHigh highTree(N + 5), highJump(N + 5);
    long long rs = 0;
    for (int i = 1; i < N; i++) {
        if (i > 1) {
            lowJump.reset(), highJump.reset();
            for (int t = 0; t < g[i - 2].size(); t++) {
                lowJump.update(t, f[i - 2][t][1]);
                highJump.update(t, f[i - 2][t][1] + calcCostRight(i - 1, g[i - 2][t].first));
            }
        }
        lowTree.reset(), highTree.reset();
        for (int t = 0; t < g[i - 1].size(); t++) {
            lowTree.update(t, f[i - 1][t][0] - calcCostLeft(i - 1, g[i - 1][t].first));
            highTree.update(t, f[i - 1][t][1] + calcCostRight(i, g[i - 1][t].first));
        }
        for (int j = 0; j < g[i].size(); j++) {
            if (i > 1) {
                int low = upper_bound(g[i - 2].begin(), g[i - 2].end(), ii(g[i][j].first, SINF)) - g[i - 2].begin() - 1;
                long long tmp = lowJump.get(low) + calcCostRight(i - 1, g[i][j].first);
                f[i][j][0] = max(f[i][j][0], tmp);
                f[i][j][1] = max(f[i][j][1], tmp);

                int high = low + 1;
                tmp = highJump.get(high);
                f[i][j][0] = max(f[i][j][0], tmp);
                f[i][j][1] = max(f[i][j][1], tmp);
            } else {
                long long tmp = calcCostRight(0, g[i][j].first);
                f[i][j][0] = max(f[i][j][0], tmp);
                f[i][j][1] = max(f[i][j][1], tmp);
            }

            int low = upper_bound(g[i - 1].begin(), g[i - 1].end(), ii(g[i][j].first, SINF)) - g[i - 1].begin() - 1;
            long long tmp = lowTree.get(low) + calcCostRight(i - 1, g[i][j].first);
            f[i][j][0] = max(f[i][j][0], tmp);
            f[i][j][1] = max(f[i][j][1], tmp);

            int high = lower_bound(g[i - 1].begin(), g[i - 1].end(), ii(g[i][j].first, 0)) - g[i - 1].begin();
            f[i][j][1] = max(f[i][j][1], highTree.get(high) - calcCostLeft(i, g[i][j].first));

            rs = max({rs, f[i][j][0], f[i][j][1]});
        }
    }
    return rs;
}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:104:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |         for (int j = 1; j < g[i].size(); j++)
      |                         ~~^~~~~~~~~~~~~
fish.cpp:114:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  114 |             for (int t = 0; t < g[i - 2].size(); t++) {
      |                             ~~^~~~~~~~~~~~~~~~~
fish.cpp:120:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |         for (int t = 0; t < g[i - 1].size(); t++) {
      |                         ~~^~~~~~~~~~~~~~~~~
fish.cpp:124:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |         for (int j = 0; j < g[i].size(); j++) {
      |                         ~~^~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 9 / 9
• Subtask 4: 14 / 14
• Subtask 5: 21 / 21
• Subtask 6: 17 / 17
• Subtask 7: 14 / 14
• Subtask 8: 16 / 16