Submission #1042278

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042278		VMaksimoski008	Catfish Farm (IOI22_fish)	C++17	12 / 100	222 ms	156836 KiB

fish

#include "fish.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

ll pref[3005][3005], dp[3005][3005][2], pmx1[3005][3005], smx1[3005][3005], pmx2[3005][3005], smx2[3005][3005];
 
ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    int mask = 0, mx = 0, mx2 = 0;
    for(int i=0; i<M; i++) mask |= (1 << (X[i] % 2));
    for(int i=0; i<M; i++) mx = max(mx, Y[i]);
    for(int i=0; i<M; i++) mx2 = max(mx, X[i]);
 
    if(mask == 1) {
        ll ans = 0;
        for(int &x : W) ans += x;
        return ans;
    }

    if(mx == 0) {
        vector<ll> val(N+5), dp(N+5);
        for(int i=0; i<M; i++) val[X[i]] = W[i];
 
        ll ans = 0;
        vector<ll> MX(N+5); MX[0] = val[1];
        for(int i=1; i<N; i++) {
            dp[i] = max(dp[i-1], val[i-1]);
            if(i >= 3) dp[i] = max(dp[i], MX[i-3] + val[i-1]);
            if(i >= 2) dp[i] = max(dp[i], dp[i-2] + val[i-1]);
            MX[i] = max(MX[i-1], dp[i] + val[i+1]);
        }
 
        for(int i=0; i<N; i++) ans = max(ans, dp[i] + val[i+1]);
        return ans;
    }

    for(int i=0; i<M; i++) pref[X[i]+1][Y[i]+1] += W[i];
    for(int i=1; i<=N; i++)
        for(int j=1; j<=N; j++) pref[i][j] += pref[i][j-1];
    for(int i=1; i<=N; i++)
        for(int j=0; j<=N; j++) pmx1[i][j] = smx1[i][j] = pmx2[i][j] = smx2[i][j] = -1e18;

    if(mx2 <= 1) {
        if(N == 2) return max(pref[1][2], pref[2][2]);
        ll ans = 0;
        for(int i=1; i<=N; i++) ans = max(ans, pref[1][i] + pref[2][N] - pref[2][i]);
        return max({ pref[1][N], pref[2][N], ans });
    }

    pmx1[1][0] = dp[1][0][1] - pref[1][0];
    smx1[1][N] = max(dp[1][N][0], dp[1][N][1]) + pref[2][N];
    for(int i=1; i<=N; i++) pmx1[1][i] = max(pmx1[1][i-1], dp[1][i][1] - pref[1][i]);
    for(int i=N-1; i>=0; i--) smx1[1][i] = max(smx1[1][i+1], max(dp[1][i][0], dp[1][i][1]) + pref[2][i]);
    for(int i=1; i<=N; i++) pmx2[1][i] = max(pmx2[1][i-1], max(dp[1][i][0], dp[1][i][1]));
    for(int i=N-1; i>=0; i--) smx2[1][i] = max(smx2[i][i+1], max(dp[1][i][0], dp[1][i][1]));

    for(int i=2; i<=N; i++) {
        for(int j=0; j<=N; j++) {
            dp[i][j][0] = max(dp[i][j][0], smx1[i-1][j] - pref[i][j]);
            dp[i][j][1] = max({ dp[i][j][1], pmx1[i-1][j] + pref[i-1][j] });
            if(i >= 3) dp[i][j][0] = max({ dp[i][j][0], pmx2[i-2][j] + pref[i-1][j], smx2[i-2][j] + pref[i-1][j] });
            if(i >= 3) dp[i][j][1] = max({ dp[i][j][1], pmx2[i-2][j] + pref[i-1][j], smx2[i-2][j] + pref[i-1][j] });

            if(j) pmx1[i][j] = pmx1[i][j-1];
            if(j) pmx2[i][j] = pmx2[i][j-1];
            pmx1[i][j] = max(pmx1[i][j], dp[i][j][1] - pref[i][j]);
            pmx2[i][j] = max(pmx2[i][j], max(dp[i][j][0], dp[i][j][1]));
        }

        smx1[i][N] = max(dp[i][N][0], dp[i][N][1]) + pref[i+1][N];
        for(int j=N-1; j>=0; j--) smx1[i][j] = max(smx1[i][j+1], max(dp[i][j][0], dp[i][j][1]) + pref[i+1][j]);
        smx2[i][N] = max(dp[i][N][0], dp[i][N][1]);
        for(int j=N-1; j>=0; j--) smx2[i][j] = max(smx2[i][j+1], max(dp[i][j][0], dp[i][j][1]));
    }

    ll ans = 0;
    for(int i=1; i<=N; i++)
        for(int j=1; j<=N; j++) ans = max({ ans, dp[i][j][0] + pref[i+1][j], dp[i][j][1] + pref[i+1][j] });
    return ans;
}

• Subtask 1: 3 / 3
• Subtask 2: 0 / 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