Submission #1079705

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079705		ArthuroWich	Catfish Farm (IOI22_fish)	C++17	100 / 100	239 ms	38632 KiB

fish

#include "fish.h"
#include<bits/stdc++.h>
using namespace std;
#define int long long int
vector<vector<int>> ind;
vector<vector<pair<int, int>>> pref;
int query(int i, int j) {
    pair<int, int> c = {j, INT64_MAX};
    auto ind = upper_bound(pref[i].begin(), pref[i].end(), c);
    ind--;
    c = *ind;
    return c.second;
}
int max_weights(int32_t N, int32_t M, vector<int32_t> X, vector<int32_t> Y, vector<int32_t> W) {
    int n = N, m = M;
    pref.resize(n+5, vector<pair<int, int>>(1, {INT64_MIN, 0}));
    ind.resize(n+5);
    for (int i = 0; i < m; i++) {
        pref[X[i]+1].push_back({Y[i], W[i]});
    }
    for (int i = 0; i <= n; i++) {
        sort(pref[i].begin(), pref[i].end());
    }
    for (int i = 0; i <= n; i++) {
        for (int j = 1; j < pref[i].size(); j++) {
            pref[i][j].second += pref[i][j-1].second;
        }
    }
    ind[0].push_back(-1);
    ind[n+1].push_back(-1);
    for (int i = 1; i <= n; i++) {
        for (auto [a, b] : pref[i-1]) {
            ind[i].push_back(a);
        }
        for (auto [a, b] : pref[i+1]) {
            ind[i].push_back(a);
        }
        sort(ind[i].begin(), ind[i].end());
        ind[i].erase(unique(ind[i].begin(), ind[i].end()), ind[i].end());
    }
    vector<vector<int>> dp(2, vector<int>(ind[0].size()+5, 0)); // 0 is increasing, 1 is decreasing, increasing can go to decreasing, decreasing cant go to increasing if next to eachother
    for (int j = 1; j <= n+1; j++) {
        vector<vector<int>> tdp(2, vector<int>(ind[j].size()+5, 0));
        int v = 0, k = 0;
        for (int i = 0; i < ind[j].size(); i++) {
            int x = ind[j][i];
            while(k < ind[j-1].size() && ind[j-1][k] <= x) {
                v = max(v, dp[0][k]-query(j-1, ind[j-1][k]));
                k++;
            }
            tdp[0][i] = max(v+query(j-1, x), dp[1][0]);
        }
        v = 0;
        k = ind[j-1].size();
        for (int i = ind[j].size()-1; i >= 0; i--) {
            int x = ind[j][i];
            while(k > 0 && ind[j-1][k-1] >= x) {
                k--;
                v = max(v, max(dp[0][k], dp[1][k])+query(j, ind[j-1][k]));
            }
            tdp[1][i] = v-query(j, x);
        }
        swap(dp[0], tdp[0]);
        swap(dp[1], tdp[1]);
    }
    int ans = max(dp[0][0], dp[1][0]);
    return ans;
}

Compilation message (stderr)

fish.cpp: In function 'long long int max_weights(int32_t, int32_t, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:25:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |         for (int j = 1; j < pref[i].size(); j++) {
      |                         ~~^~~~~~~~~~~~~~~~
fish.cpp:45:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |         for (int i = 0; i < ind[j].size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~
fish.cpp:47:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |             while(k < ind[j-1].size() && ind[j-1][k] <= x) {
      |                   ~~^~~~~~~~~~~~~~~~~

• 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