Submission #950845

#	Time	Username	Problem	Language	Result	Execution time	Memory
950845		sysia	Catfish Farm (IOI22_fish)	C++17	100 / 100	355 ms	47284 KiB

fish

//Sylwia Sapkowska
#include <bits/stdc++.h>
#include "fish.h"
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

typedef long long ll;
typedef pair<int, int> T;
const ll oo = 1e18;

void ckmax(ll &a, ll b){
    a = max(a, b);
}

ll max_weights(int n, int m, vector<int>x, vector<int>y, vector<int>w){
    vector<vector<T>>where(n+2);
    vector<vector<ll>>valid(n+1), pref(n+1);
    for (int i = 0; i<m; i++){
        where[x[i]+1].emplace_back(y[i]+1, w[i]);
    }
    valid[0].emplace_back(0);
    where[0].emplace_back(0, 0);
    pref[0].emplace_back(0);
    for (int i = 1; i<=n; i++){
        valid[i].emplace_back(0);
        for (auto [j, val]: where[i]) valid[i].emplace_back(j-1);
        for (auto [j, val]: where[i-1]) valid[i].emplace_back(j);
        for (auto [j, val]: where[i+1]) valid[i].emplace_back(j);
        sort(valid[i].begin(), valid[i].end());
        where[i].emplace_back(0, 0);
        sort(where[i].begin(), where[i].end());
        pref[i].resize((int)where[i].size());
        for (int j = 1; j<(int)where[i].size(); j++) pref[i][j] = pref[i][j-1] + (ll)where[i][j].second;
        valid[i].erase(unique(valid[i].begin(), valid[i].end()), valid[i].end());
        debug(i, where[i], pref[i], valid[i]);
    }
    vector dp(1, vector<ll>(3, -oo));
    dp[0][0] = 0;
    dp[0][1] = 0;
    auto less = [&](int i, int h){//ostatni <= h w where[i]
        int l = 0, r = (int)where[i].size()-1;
        int ans = 0;
        while (r >= l){
            int m = (l+r)/2;
            if (where[i][m].first <= h){
                ans = m;
                l = m+1;
            } else r = m-1;
        }
        return ans;
    };
    for (int i = 1; i<=n; i++){
        int s = (int)valid[i].size();
        int t = (int)valid[i-1].size();
        vector new_dp(s, vector<ll>(3, -oo));
        debug(i);
        //h = 0
        //1) poprzednia miala dodatnie pole
        for (int j = 1; j<t; j++){
            int h = valid[i-1][j];
            ckmax(new_dp[0][2], max(dp[j][1], dp[j][0]) + pref[i][less(i, h)]); //<= h
        }
        //2) poprzednia byla zerem
        new_dp[0][0] = max(dp[0][2], dp[0][0]);
        //h > 0
        //1) poprzednia byla pusta
        for (int j = 1; j<s; j++){
            int h = valid[i][j];
            new_dp[j][0] = new_dp[j][1] = max(dp[0][2], dp[0][0] + pref[i-1][less(i-1, h)]);
        }
        //2) poprzednia cos miala miau
        ll mx = -oo;
        int ptr = -1;
        for (int j = 1; j<s; j++){
            int h = valid[i][j];
            while (ptr + 1 < (int)valid[i-1].size() && valid[i-1][ptr+1] <= h){
                ptr++;
                mx = max(mx, dp[ptr][0] - pref[i-1][less(i-1, valid[i-1][ptr])]);
            }
            int tt = less(i-1, h);
            ckmax(new_dp[j][0], mx+pref[i-1][tt]);
            ckmax(new_dp[j][1], mx+pref[i-1][tt]);
        } 
        mx = -oo; ptr = t;
        for (int j = s-1; j>=1; j--){
            int h = valid[i][j];
            while (ptr >= 1 && valid[i-1][ptr-1] >= h){
                ptr--;
                mx = max(mx, dp[ptr][1] + pref[i][less(i, valid[i-1][ptr])]);
            }
            ckmax(new_dp[j][1], mx-pref[i][less(i, h)]);
        }
        for (int j = 0; j<s; j++){
            int h = valid[i][j];
            debug(h, new_dp[j]);
        }
        swap(dp, new_dp);
    }
    debug(dp);
    ll ans = 0;
    for (int j = 0; j<(int)dp.size(); j++){
        for (int rep = 0; rep < 3; rep++){
            ans = max(ans, dp[j][rep]);
        }
    }
    return ans;
}

Compilation message (stderr)

fish.cpp: In function 'll max_weights(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
fish.cpp:115:17: warning: unused variable 'h' [-Wunused-variable]
  115 |             int h = valid[i][j];
      |                 ^

• 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