Submission #824979

#	Time	Username	Problem	Language	Result	Execution time	Memory
824979		becaido	Catfish Farm (IOI22_fish)	C++17	52 / 100	1084 ms	151596 KiB

fish

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifndef WAIMAI
#include "fish.h"
#endif

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

const ll INF = 1e18;
const int SIZE = 3005;

int n, m;
ll pre[SIZE][SIZE];
ll inc[2][SIZE], dek[2][SIZE], all[2], zero[2], fzero[2];

void chmax(ll &x, ll y) {
    x = max(x, y);
}

ll max_weights(int N, int M, vector<int> X, vector<int> Y, vector<int> W) {
    n = N;
    FOR (i, 0, M - 1) {
        X[i]++, Y[i]++;
        pre[X[i]][Y[i]] += W[i];
        m = max(m, Y[i]);
    }
    all[0] = -INF;
    FOR (i, 1, m) inc[0][i] = dek[0][i] = -INF;
    FOR (i, 1, n) {
        FOR (j, 1, m) pre[i][j] += pre[i][j - 1];

        int f = i & 1;
        all[f] = zero[f] = fzero[f] = -INF;
        FOR (j, 0, m) inc[f][j] = dek[f][j] = -INF;

        ll mx = zero[!f];
        FOR (j, 1, m) {
            chmax(inc[f][j], mx + pre[i - 1][j]);
            chmax(mx, inc[!f][j] - pre[i - 1][j]);
        }

        mx = -INF;
        for (int j = m; j >= 0; j--) {
            chmax(mx, dek[!f][j] + pre[i][j]);
            chmax(dek[f][j], mx - (j ? pre[i][j] : 0));
        }

        chmax(all[f], all[!f]);
        chmax(all[f], fzero[!f]);
        chmax(all[f], inc[f][m]);

        chmax(zero[f], zero[!f]);
        chmax(zero[f], fzero[!f]);

        chmax(fzero[f], dek[f][0]);
        chmax(dek[f][m], all[f]);
    }
    ll ans = 0;
    int f = n & 1;
    chmax(ans, zero[f]);
    chmax(ans, fzero[f]);
    chmax(ans, all[f]);
    return ans;
}

/*
in1
5 4
0 2 5
1 1 2
4 4 1
3 3 3
out1
8
*/

#ifdef WAIMAI
int main() {
  int N, M;
  assert(2 == scanf("%d %d", &N, &M));

  vector<int> X(M), Y(M), W(M);
  for (int i = 0; i < M; ++i) {
    assert(3 == scanf("%d %d %d", &X[i], &Y[i], &W[i]));
  }

  long long result = max_weights(N, M, X, Y, W);
  printf("%lld\n", result);
  return 0;
}
#endif

• 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