結果

問題 No.1479 Matrix Eraser
ユーザー rabimea
提出日時 2023-01-26 22:27:58
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 131 ms / 3,000 ms
コード長 2,472 bytes
コンパイル時間 1,766 ms
コンパイル使用メモリ 201,828 KB
最終ジャッジ日時 2025-02-10 07:07:24
ジャッジサーバーID
（参考情報） 		judge1 / judge3
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 2
other AC * 39
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using pii = pair <int, int>;
//~ const ll mod = 998244353;
const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
    for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }
const int N = 511;
const int mxn = N * 2;
const int mxm = N * N * 4;
using Flow = int;
const int MXL = 1e9;
struct Flownet {
    int n, m;
    int fe[mxn];
    int ne[mxm];
    int ev[mxm];
    Flow f[mxm];
    void clear(int n) {
        this->n = n;
        fill(fe, fe + n + 1, 0);
        m = 1;
    }
    void add_(int x, int y, Flow flow) { // 添加一条边
        ne[++m] = fe[x];
        fe[x] = m;
        ev[m] = y;
        f[m] = flow;
    }
    void add1(int x, int y, Flow flow) { // 添加一条单向边和其反向边
        add_(x, y, flow);
        add_(y, x, 0);
    }
    
    int T;
    int arc[mxn], lev[mxn];
    Flow extend(int x, Flow flow) {
        if (x == T) return flow;
        Flow re = 0;
        for (int &e = arc[x]; e; e = ne[e]) if (f[e] && lev[ev[e]] == lev[x] + 1) {
            Flow t = extend(ev[e], min(flow - re, f[e]));
            if (t) {
                f[e] -= t;
                f[e ^ 1] += t;
                if ((re += t) == flow)
                    break;
            }
        }
        if (!re) lev[x] = 0;
        return re;
    }
    int q[mxn], *qb, *qe;
    Flow dinic(int S, int T) {
        this->T = T;
        Flow re = 0;
        for (;;) {
            fill(lev, lev + n + 1, 0);
            copy(fe, fe + n + 1, arc);
            lev[S] = 1;
            qb = qe = q;
            *qe++ = S;
            while (qb != qe) {
                int x = *qb++;
                if (lev[T] && lev[x] + 1 >= lev[T])
                    break;
                for (int e = fe[x]; e; e = ne[e]) if (f[e] && !lev[ev[e]]) {
                    lev[ev[e]] = lev[x] + 1;
                    *qe++ = ev[e];
                }
            }
            if (!lev[T]) break;
            re += extend(S, MXL);
        }
        return re;
    }
}net;
int vx[N], vy[N];
const int M = 5e5 + 11;
vector <pii> v[M];
int main() {
    ios :: sync_with_stdio(false);
    
    int n, m; cin >> n >> m;
    for(int i = 1; i <= n; i ++)
        for(int j = 1; j <= m; j ++) {
            int x; cin >> x;
            v[x].pb({i, j});
        }
    
    int ans = 0;
    for(int i = 1; i < M; i ++) if(v[i].size()) {
        if(v[i].size() == 1) ans ++;
        else {
            int S = 0, T = n + m + 1;
            net.clear(T);
            
            memset(vx, 0, sizeof vx);
            memset(vy, 0, sizeof vy);
            for(auto [x, y] : v[i]) {
                net.add1(x, y + n, 1);
                vx[x] = 1; vy[y] = 1;
            }
            
            for(int x = 1; x <= n; x ++)
                if(vx[x]) net.add1(S, x, 1);
            for(int y = 1; y <= m; y ++)
                if(vy[y]) net.add1(y + n, T, 1);
            
            ans += net.dinic(S, T);
        }
    }
    
    cout << ans << '\n';
}
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0