Submission #1075629

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075629		Faisal_Saqib	Catfish Farm (IOI22_fish)	C++17	70 / 100	260 ms	386544 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);
    }
    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=0;i<n;i++)
    //     for(int j=0;j<=n;j++)
    //         for(int k=0;k<2;k++)
    //             dp[i][j][k]=0;
    for(int i=1;i<n;i++)
    {
        // ll sum=0;
        ll mx1=-2e18;
        ll mx2=-2e18;
        ll mx11=0,mx22=0;
        for(int k=0;k<sz[i];k++)
        {
            int hp=possible[i][k];
            mx11=max(mx11,dp[i-1][0][k]);
            auto index=lower_bound(all(possible[i-1]),hp)-begin(possible[i-1]);
            mx1=max(mx1,dp[i-1][0][k]-pre[i-1][index]);
        }
        for(int k=0;k<sz[i];k++)
        {
            int hp=possible[i][k];
            mx11=max(mx11,dp[i-1][1][k]);

            auto index=lower_bound(all(possible[i]),hp)-begin(possible[i]);
            mx1=max(mx1,dp[i-1][1][k]+pre[i][index]);
        }
        int pp=0;
        for(auto&h:possible[i])
        {
            auto index=lower_bound(all(possible[i-1]),h)-begin(possible[i-1]);
            dp[i][0][pp]=max(dp[i][0][pp],mx1+pre[i-1][index]);
            dp[i][1][pp]=max(dp[i][1][pp],mx1+pre[i-1][index]);
            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++;
        }
    }
    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]);
        }
    }
    return ans;
}
ll subtask2(ll&n,ll&m,vll&x,vll&y,vll&w)
{
    ll ans=0;
    ll val[2][n]={0};
    for(int i=0;i<2;i++)
    {
        for(int j=0;j<n;j++)
        {
            val[i][j]=0;
        }
    }
    ll sum1=0,sum0=0;
    for(int j=0;j<m;j++)
    {
        val[x[j]][y[j]]+=w[j];
        if(x[j]==1)
        {
            sum1+=w[j];
        }
        else
        {
            sum0+=w[j];
        }
    }
    ans=max(sum0,sum1);
    ll taken=0;
    ll cur=0;
    for(int j=0;j<n;j++)
    {
        cur+=val[0][j];
        taken+=val[1][j];
        ans=max(ans,cur);
        if(n>2)
            ans=max(ans,cur+sum1-taken);
    }
    return ans;
}
ll subtask3(ll&n,ll&m,vll&x,vll&y,vll&w)
{
    ll ans=0;
    ll val[n+1];
    for(int i=0;i<n;i++)val[i]=0;
    for(int j=0;j<m;j++)val[x[j]]+=w[j];
    ll dp[n+1][3][3];
    for(int i=0;i<n;i++)
        for(int j=0;j<2;j++)
            for(int k=0;k<2;k++)
                dp[i][j][k]=0;
    for(int i=1;i<n;i++)
    {
        // wall not at i
        dp[i][0][0]=max(max(dp[i-1][0][0],dp[i-1][0][1]),dp[i-1][1][0]);
        dp[i][0][1]=max(max(dp[i-1][0][0],dp[i-1][0][1]),dp[i-1][1][0]+val[i]);

        dp[i][1][0]=max(max(dp[i-1][0][1],dp[i-1][0][0]+val[i-1]),dp[i-1][1][0]);
    }
    for(int i=0;i<n;i++)
    {
        ans=max({ans,dp[i][0][0],dp[i][0][1],dp[i][1][0],dp[i][1][1]});
    }
    return ans;
}
const int N2=3e3+1;
ll val1[N2][N2],pre1[N2][N2];
ll dp1[N2][N2][3];
ll solver(ll&n,ll&m,vll&x,vll&y,vll&w)
{
    ll ans=0;
    for(int i=0;i<n;i++)for(int j=0;j<=n;j++)val1[i][j]=pre1[i][j]=0;
    for(int j=0;j<m;j++)val1[x[j]][y[j]+1]+=w[j];
    for(int i=0;i<=n;i++)
    {
        pre1[i][0]=val1[i][0];
        for(int j=1;j<=n;j++)
            pre1[i][j]=pre1[i][j-1]+val1[i][j];
    }
    for(int i=0;i<n;i++)
        for(int j=0;j<=n;j++)
            for(int k=0;k<2;k++)
                dp1[i][j][k]=0;
    for(int i=1;i<n;i++)
    {
        // ll sum=0;
        ll mx1=-2e18;
        ll mx2=-2e18;
        ll mx11=0,mx22=0;
        for(int hp=0;hp<=n;hp++)
        {
            mx11=max(mx11,dp1[i-1][hp][0]);
            mx22=max(mx22,dp1[i-1][hp][1]);
 
            mx1=max(mx1,dp1[i-1][hp][0]-pre1[i-1][hp]);
            mx2=max(mx2,dp1[i-1][hp][1]+pre1[i][hp]);
        }
        for(int h=0;h<=n;h++)
        {
            dp1[i][h][0]=max(dp1[i][h][0],mx1+pre1[i-1][h]);
            dp1[i][h][1]=max(dp1[i][h][1],mx1+pre1[i-1][h]);
            dp1[i][h][1]=max(dp1[i][h][1],mx2-pre1[i][h]);
 
            dp1[i][h][0]=max(dp1[i][h][0],mx11);
            dp1[i][h][0]=max(dp1[i][h][0],mx22);
 
            dp1[i][h][1]=max(dp1[i][h][1],mx11);
            dp1[i][h][1]=max(dp1[i][h][1],mx22);
        }
    }
    for(int i=0;i<n;i++)
    {
        for(int h=0;h<=n;h++)
        {
            ans=max(ans,dp1[i][h][0]);
            ans=max(ans,dp1[i][h][1]);
        }
    }
    return ans;
}
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));
    ll mx_x=*max_element(all(x));
    ll mx_y=*max_element(all(y));
    if(mx_x<=1)
        return subtask2(n,m,x,y,w);
    set<ll> posmod;
    for(auto i:x)
    {
        posmod.insert(i%2);
    }
    if(posmod.size()==1 or mx_y==0)
        return subtask3(n,m,x,y,w);
    if(n<=3000)
    {
        return solver(n,m,x,y,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:36:21: 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]
   36 |             while(pp<values[i].size() and values[i][pp].first<=j)
      |                   ~~^~~~~~~~~~~~~~~~~
fish.cpp: In function 'long long int max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:217:16: warning: unused variable 'ans' [-Wunused-variable]
  217 |     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: 17 / 17
• Subtask 7: 0 / 14
• Subtask 8: 0 / 16