Submission #673671

#	Time	Username	Problem	Language	Result	Execution time	Memory
673671		vjudge1	Nafta (COI15_nafta)	C++11	100 / 100	307 ms	140652 KiB

nafta

#include<bits/stdc++.h>
using namespace std;

void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << h; if(sizeof...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL

#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
#define fi first
#define se second

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
using db = long double;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;

void setIO(string NAME = "") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(NAME)) {
        freopen((NAME + ".inp").c_str(),"r",stdin);
        freopen((NAME + ".out").c_str(),"w",stdout);
    }
}

tcT> bool ckmin(T&a, const T&b) {
    return b < a ? a=b,1 : 0; }
tcT> bool ckmax(T&a, const T&b) {
    return b > a ? a=b,1 : 0; }

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};

const int MOD = 1e9 + 7;
const ll INF = 1e18;

const int MX = 2005;

int N, M;

V<pi> lst[MX];
bool vis[MX][MX];

str s[MX];

bool isInside(int r, int c) {
    return min(r, c) >= 1 && r <= N && c <= M;
}

void dfs(int row, int col, int &l, int &r, int &sum) {
    vis[row][col] = true;
    sum += s[row][col] - '0';
    ckmin(l, col);
    ckmax(r, col);
    F0R(i, 4) {
        int nrow = row + dx[i], ncol = col + dy[i];
        if(isInside(nrow, ncol) && !vis[nrow][ncol] && s[nrow][ncol] != '.') {
            dfs(nrow, ncol, l, r, sum);
        }
    }
}

int cursum[MX];
int cost[MX][MX];

int dp[MX][MX];

void dnc(int k, int l, int r, int optl, int optr) {
    if(l > r) return;
    int mid = (l + r) >> 1;
    dp[k][mid] = -MOD;
    int opt = -1;
    FOR(j, optl, min(mid,optr)+1) if(ckmax(dp[k][mid], dp[k-1][j] + cost[j][mid])) {
        opt = j;
    }

    dnc(k, l, mid-1, optl, opt);
    dnc(k, mid+1, r, opt, optr);
}

void solve() {
    cin >> N >> M;
    FOR(i,1,N+1) {
        cin >> s[i];
        s[i] = '$' + s[i];
    }
    FOR(i,1,N+1) FOR(j,1,M+1) if(!vis[i][j] && s[i][j] != '.') {
        int l, r, sum;
        l = MOD, r = -MOD, sum = 0;
        dfs(i, j, l, r, sum);
        lst[r].pb({l, sum});
    }
    ROF(i,1,M+1) {
        each(p, lst[i]) {
            ROF(j, p.fi, i+1) {
                cursum[j] += p.se;
            }
        }
        R0F(j, i+1) {
            cost[j][i] = cursum[i] - cursum[j];
        }
    }
    memset(dp, -0x3f, sizeof dp);
    dp[0][0] = 0;
    FOR(k,1,M+1) {
        dnc(k, 1, M, 0, M-1);
        int res = -MOD;
        FOR(i,1,M+1) ckmax(res, dp[k][i]);
        cout << res << nl;
    }
}

int main() {
    setIO();

    int t=1;
    //cin>>t;
    while(t-->0) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

nafta.cpp: In function 'void setIO(std::string)':
nafta.cpp:40:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         freopen((NAME + ".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nafta.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |         freopen((NAME + ".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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