Submission #769473

#	Time	Username	Problem	Language	Result	Execution time	Memory
769473		mousebeaver	Catfish Farm (IOI22_fish)	C++17	18 / 100	71 ms	10420 KiB

fish

#define ll long long
#define pll pair<ll, ll>
#include "fish.h"
#include <bits/stdc++.h>
using namespace std;

long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y, std::vector<int> W) 
{
    bool sub1 = true;
    bool sub2 = true;
    bool sub3 = true;

    for(ll i = 0; i < M; i++)
    {
        if(X[i] % 2 == 1)
        {
            sub1 = false;
        }
        if(X[i] > 1)
        {
            sub2 = false;
        }
        if(Y[i] != 0)
        {
            sub3 = false;
        }
    }

    if(sub1)
    {
        ll sum = 0;
        for(int i : W)
        {
            sum += (ll) i;
        }
        return sum;
    }
    if(sub2)
    {
        vector<pll> left(0);
        vector<pll> right(0); //Height, weight
        ll lsum = 0;
        ll rsum = 0;

        for(ll i = 0; i < M; i++)
        {
            if(X[i] == 0)
            {
                left.push_back({Y[i], W[i]});
                lsum += W[i];
            }
            else
            {
                right.push_back({Y[i], W[i]});
                rsum += W[i];
            }
        }
        sort(left.begin(), left.end());
        sort(right.begin(), right.end());

        ll output = max(lsum, rsum);

        if(N > 2)
        {
            ll lindex = -1;
            ll rindex = -1;
            ll shadow = 0;
            ll roof = 0;
            for(ll i = 0; i < N; i++)
            {
                while(lindex+1 < (ll) left.size() && left[lindex+1].first <= i)
                {
                    lindex++;
                    shadow += left[lindex].second;
                }
                while(rindex+1 < (ll) right.size() && right[rindex+1].first <= i)
                {
                    rindex++;
                    roof += right[rindex].second;
                }
                output = max(output, shadow + rsum - roof);
            }
        }

        return output;
    }
    if(sub3)
    {
        vector<ll> w(N, 0);
        for(ll i = 0; i < M; i++)
        {
            w[X[i]] = W[i];
        }

        vector<vector<ll>> dp(N, vector<ll> (3, 0)); //Pier, no pier + uncaught, no pier + caught
        for(ll i = 1; i < N; i++)
        {
            //Pier:
            dp[i][0] = dp[i-1][0];
            dp[i][0] = max(dp[i][0], dp[i-1][1]+w[i-1]);
            dp[i][0] = max(dp[i][0], dp[i-1][2]);

            //no pier + uncaught:
            dp[i][1] = dp[i-1][1];
            dp[i][1] = max(dp[i][1], dp[i-1][2]);

            //no pier + caught:
            dp[i][2] = dp[i-1][0]+w[i];
        }

        return max(max(dp[N-1][0], dp[N-1][1]), dp[N-1][2]);
    }
    
    return 0;
}

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 9 / 9
• Subtask 4: 0 / 14
• Subtask 5: 0 / 21
• Subtask 6: 0 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16