Submission #1076300

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076300		Faisal_Saqib	Catfish Farm (IOI22_fish)	C++17	53 / 100	290 ms	88224 KiB

fish

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vll vector<ll>
#define all(x) begin(x),end(x)
const int N=1e5+10;
vll pre[N];
ll sz[N];
vll dp[N][3];
vll possible[N];
vector<pair<ll,ll>> values[N];
ll solve(ll&n,ll&m,vll&x,vll&y,vll&w)
{
    ll ans=0;
    for(int j=0;j<m;j++)
    {
        values[x[j]].push_back({y[j]+1,w[j]});
        possible[x[j]].push_back(y[j]+1);
        possible[x[j]+1].push_back(y[j]+1);
        if(x[j]>0)
            possible[x[j]-1].push_back(y[j]+1);
        // cout<<"AT "<<x[j]<<' '<<y[j]+1<<endl;
    }
    for(int i=0;i<=n;i++)
    {
        possible[i].push_back(0);
        possible[i].push_back(n);
        sort(begin(possible[i]),end(possible[i]));
        sort(begin(values[i]),end(values[i]));
        sz[i]=possible[i].size();
        pre[i].resize(sz[i]+1,0);
        ll sm=0;
        int pp=0;
        int rp=0;
        for(auto&j:possible[i])
        {
            while(pp<values[i].size() and values[i][pp].first<=j)
            {
                sm+=values[i][pp].second;
                pp++;
            }
            pre[i][rp]=sm;
            rp++;
        }
        dp[i][0].resize(sz[i]+1,0);
        dp[i][1].resize(sz[i]+1,0);
    }
    for(int i=1;i<n;i++)
    {
        // ll sum=0;
        ll mx1=-1e18;
        ll mx2=-1e18;
        ll mx11=0,mx22=0;
        for(int k=0;k<sz[i-1];k++)
        {
            int hp=possible[i-1][k];
            mx11=max(mx11,dp[i-1][0][k]);
            mx1=max(mx1,dp[i-1][0][k]-pre[i-1][k]);
        }
        for(int k=0;k<sz[i-1];k++)
        {
            int hp=possible[i-1][k];
            mx22=max(mx22,dp[i-1][1][k]);
            auto index=lower_bound(all(possible[i]),hp);
            if(index!=end(possible[i]))
            {
                int ind=index-begin(possible[i]);
                mx2=max(mx2,dp[i-1][1][k]+pre[i][ind]);
            }
        }
        // cout<<"For "<<i<<' '<<mx1<<' '<<mx2<<' '<<mx11<<' '<<mx22<<endl;
        int pp=0;
        for(auto&h:possible[i])
        {
            auto index=lower_bound(all(possible[i-1]),h);
            // if(possible[i-1][index]!=h)
            // {
            //     cout<<"Fudge\n";
            //     cout<<i-1<<' '<<index<<' '<<h<<endl;
            //     for(auto jp:possible[i-1])
            //     {
            //         cout<<jp<<' ';
            //     }
            //     cout<<endl;
            // }
            if(index!=end(possible[i-1]))
            {
                int ind=index-begin(possible[i-1]);
                dp[i][0][pp]=max(dp[i][0][pp],mx1+pre[i-1][ind]);
                dp[i][1][pp]=max(dp[i][1][pp],mx1+pre[i-1][ind]);
            }
            // else
            // {
            //     dp[i][0][pp]=max(dp[i][0][pp],mx1);
            //     dp[i][1][pp]=max(dp[i][1][pp],mx1);
            // }
            dp[i][1][pp]=max(dp[i][1][pp],mx2-pre[i][pp]);

            dp[i][0][pp]=max(dp[i][0][pp],mx11);
            dp[i][0][pp]=max(dp[i][0][pp],mx22);

            dp[i][1][pp]=max(dp[i][1][pp],mx11);
            dp[i][1][pp]=max(dp[i][1][pp],mx22);
            pp++;
        }
    }
    // cout<<"Then\n";
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<sz[i];j++)
        {
            ans=max(ans,dp[i][0][j]);
            ans=max(ans,dp[i][1][j]);
            // cout<<i<<' '<<possible[i][j]<<' '<<0<<' '<<dp[i][0][j]<<endl;
            // cout<<i<<' '<<possible[i][j]<<' '<<1<<' '<<dp[i][1][j]<<endl;
        }
    }
    return ans;
}
// long long max_weights(int N, int M, std::vector<ll> X, std::vector<ll> Y,std::vector<ll> W)
long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y,std::vector<int> W)
{
    ll n=N,m=M,ans=0;
    vector<ll> x(all(X)),y(all(Y)),w(all(W));
    return solve(n,m,x,y,w);
}

Compilation message (stderr)

fish.cpp: In function 'long long int solve(long long int&, long long int&, std::vector<long long int>&, std::vector<long long int>&, std::vector<long long int>&)':
fish.cpp:37:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |             while(pp<values[i].size() and values[i][pp].first<=j)
      |                   ~~^~~~~~~~~~~~~~~~~
fish.cpp:56:17: warning: unused variable 'hp' [-Wunused-variable]
   56 |             int hp=possible[i-1][k];
      |                 ^~
fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:123:16: warning: unused variable 'ans' [-Wunused-variable]
  123 |     ll n=N,m=M,ans=0;
      |                ^~~

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