Submission #762023

# Submission time Handle Problem Language Result Execution time Memory
762023 2023-06-20T15:00:17 Z GrindMachine Nafta (COI15_nafta) C++17
100 / 100
310 ms 134680 KB
// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
edi

*/

const int MOD = 1e9 + 7;
const int N = 2e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

struct DSU {
    vector<int> par, rankk, siz;
    vector<int> mnj, mxj, sum;

    DSU() {

    }

    DSU(int n) {
        init(n);
    }

    void init(int n) {
        par = vector<int>(n + 1);
        rankk = vector<int>(n + 1);
        siz = vector<int>(n + 1);
        mnj = vector<int>(n + 1);
        mxj = vector<int>(n + 1);
        sum = vector<int>(n + 1);

        rep(i, n + 1) create(i);
    }

    void create(int u) {
        par[u] = u;
        rankk[u] = 0;
        siz[u] = 1;
        mnj[u] = inf1;
        mxj[u] = -inf1;
        sum[u] = 0;
    }

    int find(int u) {
        if (u == par[u]) return u;
        else return par[u] = find(par[u]);
    }

    bool same(int u, int v) {
        return find(u) == find(v);
    }

    void merge(int u, int v) {
        u = find(u), v = find(v);
        if (u == v) return;

        if (rankk[u] == rankk[v]) rankk[u]++;
        if (rankk[u] < rankk[v]) swap(u, v);

        par[v] = u;
        siz[u] += siz[v];

        amin(mnj[u], mnj[v]);
        amax(mxj[u], mxj[v]);
        sum[u] += sum[v];
    }
};

int w[N][N]; // w[j][i] = sum of segs that contain i, but not j (i > j)

void go(vector<int> &dp1, vector<int> &dp2, int l, int r, int lx, int rx){
    if(l > r) return;

    int mid = (l+r) >> 1;

    int mx = -1;
    int opt_mid = -1;

    for(int i = lx; i <= rx; ++i){
        if(i >= mid) break;
        int cost = dp1[i] + w[i][mid];
        if(cost > mx){
            mx = cost;
            opt_mid = i;
        }
    }

    dp2[mid] = mx;

    go(dp1,dp2,l,mid-1,lx,opt_mid);
    go(dp1,dp2,mid+1,r,opt_mid,rx);
}

void solve(int test_case)
{
    int n,m; cin >> n >> m;
    int a[n+5][m+5];
    memset(a,-1,sizeof a);

    rep1(i,n){
        rep1(j,m){
            char ch; cin >> ch;
            if(ch != '.'){
                a[i][j] = ch-'0';
            }
            else{
                a[i][j] = -1;
            }
        }
    }

    auto get = [&](int i, int j){
        return (i-1)*m + j;
    };

    DSU dsu(n*m+5);
    vector<pll> dir = {{0,1},{1,0}};

    rep1(i,n){
        rep1(j,m){
            int ind = get(i,j);
            dsu.mnj[ind] = dsu.mxj[ind] = j;
            dsu.sum[ind] = a[i][j];
        }
    }

    rep1(i,n){
        rep1(j,m){
            if(a[i][j] == -1) conts;

            for(auto [dx,dy] : dir){
                int i2 = i + dx;
                int j2 = j + dy;

                if(a[i2][j2] != -1){
                    dsu.merge(get(i,j), get(i2,j2));
                }
            }
        }
    }

    vector<int> enter[m+5];
    vector<pii> leave[m+5];

    rep1(i,n){
        rep1(j,m){
            if(a[i][j] == -1) conts;
            int ind = get(i,j);

            if(dsu.find(ind) == ind){
                int l = dsu.mnj[ind];
                int r = dsu.mxj[ind];
                int w = dsu.sum[ind];

                enter[l].pb(w);
                leave[r+1].pb({l,w});

                // vector<int> t = {l,r,w};
                // debug(t);
            }
        }
    }

    vector<int> sum_here(m+5);
    rep1(i,m){
        trav(w,enter[i]){
            sum_here[i-1] += w;
        }
        for(auto [l,w] : leave[i]){
            sum_here[l-1] -= w;
        }

        vector<ll> suff(m+5);
        rev(j,i,0) suff[j] += suff[j+1] + sum_here[j];

        rep(j,i+1){
            w[j][i] = suff[j];
        }
    }

    vector<int> dp1(m+5,-inf1);
    dp1[0] = 0;

    rep1(j,m){
        vector<int> dp2(m+5,-inf1);
        go(dp1,dp2,1,m,0,m);        
        
        dp1 = dp2;
        int ans = *max_element(all(dp2));
        cout << ans << endl;
    }

    // rep1(j,m){
    //     rep1(i,m){
    //         rep(k,i){
    //             amax(dp2[i], w[k][i] + dp1[k]);
    //         }
    //     }

    //     dp1 = dp2;

    //     int ans = *max_element(all(dp2));
    //     cout << ans << endl;        
    // }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}
# Verdict Execution time Memory Grader output
1 Correct 1 ms 584 KB Output is correct
2 Correct 1 ms 596 KB Output is correct
3 Correct 1 ms 580 KB Output is correct
4 Correct 1 ms 584 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Correct 1 ms 596 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 584 KB Output is correct
2 Correct 1 ms 596 KB Output is correct
3 Correct 1 ms 580 KB Output is correct
4 Correct 1 ms 584 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Correct 1 ms 596 KB Output is correct
7 Correct 6 ms 4440 KB Output is correct
8 Correct 7 ms 4436 KB Output is correct
9 Correct 7 ms 4236 KB Output is correct
10 Correct 6 ms 4440 KB Output is correct
11 Correct 5 ms 4308 KB Output is correct
12 Correct 5 ms 4308 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 584 KB Output is correct
2 Correct 1 ms 596 KB Output is correct
3 Correct 1 ms 580 KB Output is correct
4 Correct 1 ms 584 KB Output is correct
5 Correct 1 ms 596 KB Output is correct
6 Correct 1 ms 596 KB Output is correct
7 Correct 6 ms 4440 KB Output is correct
8 Correct 7 ms 4436 KB Output is correct
9 Correct 7 ms 4236 KB Output is correct
10 Correct 6 ms 4440 KB Output is correct
11 Correct 5 ms 4308 KB Output is correct
12 Correct 5 ms 4308 KB Output is correct
13 Correct 296 ms 134680 KB Output is correct
14 Correct 310 ms 133328 KB Output is correct
15 Correct 282 ms 128412 KB Output is correct
16 Correct 211 ms 132504 KB Output is correct
17 Correct 225 ms 128156 KB Output is correct
18 Correct 213 ms 128008 KB Output is correct