Submission #829301

#	Time	Username	Problem	Language	Result	Execution time	Memory
829301		otarius	Catfish Farm (IOI22_fish)	C++17	100 / 100	198 ms	44140 KiB

fish

#include "fish.h"
#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <cstring>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
using namespace std;
 
#define ff first
#define sc second
#define pb push_back
#define ll long long
#define pll pair<ll, ll>
#define pii pair <int, int>
#define ull unsigned long long
 
// #define int long long
// #define int unsigned long long
 
const ll inf = 1e18;
const ll weirdMod = 998244353;
 
int n, m, y, w;
struct fentree {
    ll t[100005];
    void init() {
        for (int i = 1; i <= n; i++) t[i] = -inf;
    }
    
    void update(int i, ll k) {
        for ( ; i <= n; i += (i & -i)) t[i] = max(t[i], k);
    }
    
    ll query(int i) {
        ll ans = -inf;
        for ( ; i; i -= (i & -i)) ans = max(ans, t[i]);
        return ans;
    }
} t1, t2;
 
vector<pll> pos[100005];
vector<ll> dp1[100005];
vector<ll> dp2[100005];
ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    n = N; m = M;
    
    for (int i = 0; i < M; i++) {
        X[i]++; Y[i]++;
        pos[X[i]].pb({Y[i], W[i]});
    }
    for (int i = 0; i <= n + 1; i++) {
        sort(pos[i].begin(), pos[i].end());
        if (pos[i].empty() || pos[i][0].ff != 1) pos[i].pb({1, 0});
        sort(pos[i].begin(), pos[i].end());
        if (pos[i].back().ff != n) pos[i].pb({n, 0});
        
        dp1[i] = vector<ll>(pos[i].size(), -inf);
        dp2[i] = vector<ll>(pos[i].size(), -inf);
    }
    
    t1.init(); t2.init();
    
    dp1[0][dp1[0].size() - 1] = 0; dp2[0][0] = 0;
    ll a = -inf, b = -inf, ans = 0;
    for (int i = 0; i <= n + 1; i++) {
        int k = pos[i].size();
        
        if (i >= 1) a = max(a, dp2[i - 1][0]);
        if (i >= 2) b = max(b, dp1[i - 2].back());
        
        dp1[i][0] = max(dp1[i][0], a + pos[i][0].sc);
        if (i >= 2) dp1[i][0] = max(dp1[i][0], dp1[i - 2].back() + pos[i][0].sc);
        dp2[i][k - 1] = max(dp2[i][k - 1], b + pos[i][k - 1].sc);
        
        for (int j = 0; j < k; j++) {
            y = pos[i][j].ff;
            w = pos[i][j].sc;
            
            dp1[i][j] = max(dp1[i][j], t1.query(y - 1) + w);
            t1.update(y, dp1[i][j]);
        }
        
        for (int j = k - 1; j >= 0; j--) {
            y = pos[i][j].ff;
            w = pos[i][j].sc;
            
            dp2[i][j] = max(dp2[i][j], t2.query(n - y) + w);
            t2.update(n - y + 1, dp2[i][j]);
        }
        
        ans = max(ans, dp2[i][0]);
    }
    
    return ans;
}

• 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