Submission #626202

#	Time	Username	Problem	Language	Result	Execution time	Memory
626202		mraron	Catfish Farm (IOI22_fish)	C++17	100 / 100	231 ms	19840 KiB

fish

#include "fish.h"

#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;

using ll = long long ;

#define sz(x) (int)(x).size()
#define xx first
#define yy second

//dp0[i][j] -> i. oszlopban j-ig elé építve piert max hogyha mindkettő szomszédosnál magasabb
//dp1[i][j] -> i. oszlopban j-ig elé építve piert max hogyha bal oldali számít
//dp2[i][j] -> i. oszlopban j-ig elé építve piert max hogyha jobb oldali számít


long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y,
                      std::vector<int> W) {
    vector<vector<pair<int,ll>>> lst(N+2, vector<pair<int,ll>>());
    for(int i=0;i<M;++i) {
        lst[X[i]].push_back({Y[i], W[i]});
    }

    for(int i=0;i<=N+1;++i) lst[i].push_back({N+10,0});
    for(auto& i:lst) sort(i.begin(), i.end());
    for(auto& i:lst) 
        for(int j=1;j<sz(i);++j) i[j].yy+=i[j-1].yy;
    
    auto get_bal=[&](int x, int l) -> ll {
          auto itL=lower_bound(lst[x].begin(), lst[x].end(), make_pair(l, 0LL));
          return (itL==lst[x].begin()?0:prev(itL)->yy);
    };
    
    auto get_jobb=[&](int x, int r) -> ll {
          auto itR=lower_bound(lst[x].begin(), lst[x].end(), make_pair(r+1, 0LL));
          return (itR==lst[x].begin()?0:prev(itR)->yy);
    };
    
    auto get_sum=[&](int x, int l, int r) -> ll {
        if(l>r) return 0;
        //~ ll sum=0;
        //~ for(int i=0;i<sz(lst[x]);++i) {
            //~ if(l<=lst[x][i].xx && lst[x][i].xx<=r) sum+=lst[x][i].yy;
        //~ }
        //~ cerr<<x<<","<<l<<","<<r<<" -> "<<sum<<"\n";
        ll sum=get_jobb(x, r)-get_bal(x, l);
        return sum;
    };
    
    
    vector<ll> dp0(lst[0].size());
    vector<ll> dp1(lst[0].size());
    vector<ll> dp2(lst[0].size());
    for(int i=1;i<N;++i) {
        vector<ll> ndp0(lst[i].size());
        vector<ll> ndp1(lst[i].size());
        vector<ll> ndp2(lst[i].size());
        
        ll mxdp0=*max_element(dp0.begin(), dp0.end());
        ll mxdp1=*max_element(dp1.begin(), dp1.end());
        ll mxdp2=*max_element(dp2.begin(), dp2.end());
        
        //dp0
        int k=0;
        ll mx=0;
        for(int j=0;j<sz(lst[i]);++j) {
            ndp0[j]=mxdp1;
            for(;k<sz(lst[i-1]);++k) {
                if(lst[i-1][k].xx>lst[i][j].xx-1) break ;
                mx=max(mx, dp2[k]-get_bal(i-1, lst[i-1][k].xx));
            }
            ndp0[j]=max({ndp0[j], get_jobb(i-1, lst[i][j].xx-1)+mx});
        }
        
        //dp1
        k=sz(lst[i-1])-1;
        ll mx0=0, mx1=0;
        for(int j=0;j<sz(lst[i]);++j) {
            ndp1[j]=max(mxdp0, mxdp1);
            for(;k>=0;--k) {
                if(lst[i][j].xx>lst[i-1][k].xx-1) break ;
                mx0=max(mx0, dp0[k]+get_jobb(i, lst[i-1][k].xx-1));
                mx1=max(mx1, dp1[k]+get_jobb(i, lst[i-1][k].xx-1));
            }
            ndp1[j]=max({ndp1[j], max(mx0,mx1)-get_bal(i, lst[i][j].xx)});
        }
        
        //dp2
        k=0;
        mx=0;
        for(int j=0;j<sz(lst[i]);++j) {
            ndp2[j]=max(mxdp0, mxdp1);
            for(;k<sz(lst[i-1]);++k) {
                if(lst[i-1][k].xx>lst[i][j].xx-1) break ;
                mx=max(mx, dp2[k]-get_bal(i-1, lst[i-1][k].xx));
            }
            ndp2[j]=max({ndp2[j], get_jobb(i-1, lst[i][j].xx-1)+mx});
        }
        //~ cerr<<i<<", 0: "; for(auto j:ndp0) cerr<<j<<" ";cerr<<"\n";
        //~ cerr<<i<<", 1: "; for(auto j:ndp1) cerr<<j<<" ";cerr<<"\n";
        //~ cerr<<i<<", 2: "; for(auto j:ndp2) cerr<<j<<" ";cerr<<"\n\n";
        dp0.swap(ndp0);
        dp1.swap(ndp1);
        dp2.swap(ndp2);
    }
    
    return max({
        *max_element(dp0.begin(), dp0.end()),
        *max_element(dp1.begin(), dp1.end()),
        *max_element(dp2.begin(), dp2.end())
    });
        
}

    

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:63:12: warning: unused variable 'mxdp2' [-Wunused-variable]
   63 |         ll mxdp2=*max_element(dp2.begin(), dp2.end());
      |            ^~~~~
fish.cpp:41:10: warning: variable 'get_sum' set but not used [-Wunused-but-set-variable]
   41 |     auto get_sum=[&](int x, int l, int r) -> ll {
      |          ^~~~~~~

• 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