Submission #1250842

#	Time	Username	Problem	Language	Result	Execution time	Memory
1250842		NoLove	Nafta (COI15_nafta)	C++20	11 / 100	1096 ms	6300 KiB

nafta

/**
 *    author : Lăng Trọng Đạt
 *    created: 02-08-2025 
**/
#include <bits/stdc++.h>
using namespace std;
#ifndef LANG_DAT
#define db(...) ;
#endif // LANG_DAT
#define int long long
#define f first
#define se second
#define pb push_back
#define all(v) (v).begin(), (v).end()
#define FOR(i, a, b) for (int i = (a); (i) <= (b); (i++))
#define FD(i, lo, up) for (int i = (up); (i) >= (lo); i--)
#define si(x) (int)(x.size())
bool mx(int& a, int b) { if (b > a) {a = b; return true;} return false;}
bool mi(int& a, int b) { if (b < a) {a = b; return true;} return false;}
using pii = pair<int, int>;
using vi = vector<int>;
const int INF = 1e18 + 5;
const int MOD = 1e9 + 7;

const int N = 2e3 + 5;
int g[N][N];
int n, m, k, q, a, b, c;

int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
int comp[N][N], sum[N * N], trai[N * N], comp_cnt = 0;
void pre() {
    FOR(i, 1, n) FOR(j, 1, m) {
        if (comp[i][j] == 0 && g[i][j] != -1) {
            trai[++comp_cnt] = m + 1;
            queue<pii> q; 
            q.push({i, j});
            while (si(q)) {
                auto[x, y] = q.front(); q.pop();
                if (1 <= x && x <= n && 1 <= y && y <= m && g[x][y] != -1 && !comp[x][y]) {
                    comp[x][y] = comp_cnt;
                    sum[comp_cnt] += g[x][y]; 
                    mi(trai[comp_cnt], y);

                    FOR(k, 0, 3) {
                        q.push({x + dx[k], y + dy[k]});
                    }   
                }
            }
            // db(i, j, comp[i][j], sum[comp[i][j]], trai[comp[i][j]])
        }
    }
}

int dp[N][N]; // dp[i][j]: nếu khoan j cái và cái cuối cùng ở vị trí <= i thì tối đa là ?
int32_t main() {
    cin.tie(0)->sync_with_stdio(0);
    if (fopen("hi.inp", "r")) {
        freopen("hi.inp", "r", stdin);
//        freopen("hi.out", "w", stdout);
    } 

    cin >> n >> m;
    FOR(i, 1, n) FOR(j, 1, m) {
        char c; cin >> c;
        g[i][j] = (c == '.' ? -1 : c - '0');
    }

    pre();
    FOR(j, 1, m) {
        FOR(i, 1, m) {
            dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
            vector<vector<int>> oil;
            FOR(x, 1, n) {
                if (g[x][i] != -1) {
                    oil.push_back({trai[comp[x][i]], comp[x][i], sum[comp[x][i]]});
                }
            }
            sort(all(oil));
            oil.resize(unique(all(oil)) - oil.begin());
            reverse(all(oil));

            int add = 0;
            // for (auto[left_most, id, tong] : oil) {
            for (auto& cur : oil) {
                add += cur[2];
                mx(dp[i][j], dp[cur[0] - 1][j - 1] + add);
            }
            db(i, j, dp[i][j])
        }

        cout << dp[m][j] << "\n";
    }
}   

Compilation message (stderr)

nafta.cpp: In function 'int32_t main()':
nafta.cpp:59:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |         freopen("hi.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 0 / 23
• Subtask 3: 0 / 66