Submission #1070661

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070661		beaconmc	Catfish Farm (IOI22_fish)	C++17	52 / 100	1083 ms	727076 KiB

fish

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include "fish.h"

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)

const ll maxn = 3005;


bool fish[maxn][maxn];
ll weights[maxn][maxn];

ll p[maxn][maxn];



ll dp[maxn][maxn][2];

ll pref[maxn][maxn][2];
ll pref2[maxn][maxn][2];
ll suff[maxn][maxn][2];


long long max_weights(int N, int M, std::vector<int> X, std::vector<int> Y,
                      std::vector<int> W) {


    FOR(i,0,M){
        Y[i]++;
        fish[X[i]][Y[i]] = true;
        weights[X[i]][Y[i]] = W[i];
    }
    FOR(i,0,maxn){
        p[i][0] = 0;
        FOR(j,1,maxn){
            p[i][j] = p[i][j-1] + weights[i][j];
        }
    }

    FOR(i,0,N+1){
        FOR(j,0,N+1){
            FOR(k,0,2){


                if (i<2) continue;
                ll temp = 0;
                ll add = 0;
                if (k==0){
                    temp = max(temp, suff[i-1][j+1][0] - p[i-1][j]);
                    temp = max(temp, suff[i-1][j+1][1] - p[i-1][j]);
                    // FOR(p,j+1,N+1){
                    //     if (fish[i-1][p]) add += weights[i-1][p];
                    //     temp = max(temp, dp[i-1][p][0] + add);
                    //     temp = max(temp, dp[i-1][p][1] + add);
                    // }
                }else{
                    temp = max(temp, pref[i-1][j][0]);
                    temp = max(temp, pref[i-1][j][1] + p[i-2][j]);
                    // FOR(p,0,j+1) if (fish[i-2][p]) add += weights[i-2][p];
                    // FOR(p,0,j+1){
                    //     if (fish[i-2][p]) add -= weights[i-2][p];
                    //     temp = max(temp, dp[i-1][p][0]);
                    //     temp = max(temp, dp[i-1][p][1] + add);
                    // }
                }
                dp[i][j][k] = temp;
            }
        }

        FOR(k,0,2){
            ll tempadd = 0;
            ll tempadd2 = 0;


            FOR(j,0,N+1){
                tempadd += weights[i][j];
                suff[i][j][k] = dp[i][j][k]+tempadd;
            }

            FOR(j,0,N+1){
                if (i>1) tempadd2 -= weights[i-1][j];
                pref[i][j][k] = dp[i][j][k] + tempadd2;
                pref2[i][j][k] = dp[i][j][k];
            }

            FOR(j,1,N+1){
                pref[i][j][k] = max(pref[i][j][k], pref[i][j-1][k]);
                pref2[i][j][k] = max(pref2[i][j][k], pref2[i][j-1][k]);
            }

            FORNEG(j,N,-1){
                suff[i][j][k] = max(suff[i][j][k], suff[i][j+1][k]);
            }
        }

    }


    ll ans = 0;
    FOR(i,0,N+1) FOR(j,0,N+1)FOR(k,0,2){
        //if (dp[i][j][k]==305) cout << i << " " << j << " " << k << endl;
        ans = max(ans, dp[i][j][k]);
    }
    return ans;







}

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:52:20: warning: unused variable 'add' [-Wunused-variable]
   52 |                 ll add = 0;
      |                    ^~~

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