Submission #773057

#	Time	Username	Problem	Language	Result	Execution time	Memory
773057		hafo	Nafta (COI15_nafta)	C++14	11 / 100	8 ms	5400 KiB

nafta

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;

template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}

const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 2000 + 7;
const ll oo = 1e18 + 69;

int n, m, id[maxn][maxn], num_gr = 0, cost[maxn][maxn], dp[maxn][maxn];
char a[maxn][maxn];
struct group {
    int l, r, oil;
};
vector<group> cpn;
pa d[] = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
bool used[maxn];

void bfs(int sx, int sy) {
    id[sx][sy] = ++num_gr;
    queue<pa> q;
    q.push({sx, sy});
    int s = 0, l = m, r = 0;

    while(!q.empty()) {
        int u = q.front().fi, v = q.front().se;
        q.pop();

        s += a[u][v] - '0';
        mini(l, v);
        maxi(r, v);

        for(int k = 0; k < 4; k++) {
            int x = u + d[k].fi, y = v + d[k].se;
            if(x < 1 || x > n || y < 1 || y > m || id[x][y] || a[x][y] == '.') continue;
            id[x][y] = num_gr;
            q.push({x, y});
        }
    }
    cpn.pb({l, r, s});
}

void solve(int t, int l, int r, int optl, int optr) {
    if(l > r) return;
    int i = l + r >> 1;
    pa res = {0, 0};
    for(int j = optl; j <= min(i - 1, optr); j++) 
        if(maxi(res.fi, dp[t - 1][j] + cost[i][j])) res.se = j;
    dp[t][i] = res.fi;
    solve(t, l, i - 1, optl, res.se);
    solve(t, i + 1, r, res.se, optr);
} 

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    //freopen(TASK".inp", "r", stdin);
    //freopen(TASK".out", "w", stdout);

    cin>>n>>m;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) cin>>a[i][j];
    }
    
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            if(id[i][j] || a[i][j] == '.') continue;
            bfs(i, j);
        }
    }

    for(int i = 1; i <= m; i++) {
        vector<pa> val;
        fill_n(used, num_gr + 1, 0);
        for(int j = 1; j <= n; j++) {
            if(!id[j][i]) continue;
            int idd = id[j][i] - 1;
            if(used[idd]) continue;
            used[idd] = 1;
            val.pb({cpn[idd].l, idd});
            cost[i][0] += cpn[idd].oil;
        }

        sort(all(val));
        int k = 0;
        for(int j = 1; j < i; j++) {
            cost[i][j] = cost[i][j - 1];
            while(k < Size(val) && val[k].fi == j) {
                cost[i][j] -= cpn[val[k].se].oil;
                k++;
            }
        }
    }

    for(int t = 1; t <= m; t++) {
        int ans = 0;
        if(t == 1) {
            for(int i = 1; i <= m; i++) dp[t][i] = cost[i][0];
        } else solve(t, 1, m, 1, m);
        for(int i = 1; i <= m; i++) maxi(ans, dp[t][i]);
        cout<<ans<<"\n";
    }
    return 0;
}

Compilation message (stderr)

nafta.cpp: In function 'void solve(int, int, int, int, int)':
nafta.cpp:57:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   57 |     int i = l + r >> 1;
      |             ~~^~~

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