結果

問題 No.421 しろくろチョコレート
ユーザー kaikey
提出日時 2020-06-03 23:04:12
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 6 ms / 2,000 ms
コード長 4,750 bytes
コンパイル時間 1,841 ms
コンパイル使用メモリ 180,496 KB
実行使用メモリ 6,944 KB
最終ジャッジ日時 2024-09-23 07:26:25
合計ジャッジ時間 3,384 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge2
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ファイルパターン 結果
other AC * 65
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;
typedef long long int lint;
typedef pair<lint, lint> plint;
typedef pair<double long, double long> pld;
#define Alint(x) (x).begin(), (x).end()
#define SZ(x) ((lint)(x).size())
#define POW2(n) (1ll << (n))
#define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(lint i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
template<typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2>& l, const pair<T1, T2>& r) { return make_pair(l.first + r.first, l
    .second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2>& l, const pair<T1, T2>& r) { return make_pair(l.first - r.first, l
    .second - r.second); }
const lint MOD = 998244353, INF = 1e9;
template<typename flow_t, typename cost_t>
struct Flow {
    const cost_t INF = pow(10, 18);
    struct edge {
        lint to;
        flow_t cap;
        cost_t cost;
        lint rev;
    };
    vector<vector<edge> > Graph;
    vector<cost_t> potential, min_cost;
    vector<lint> prevv, preve;
    vector<lint> level;
    vector<lint> iter;
    Flow(lint V) :Graph(V) {}
    void add_edge(lint from, lint to, flow_t cap, cost_t cost = 0) {
        Graph[from].push_back({ to, cap, cost, SZ(Graph[to]) });
        Graph[to].push_back({ from, 0, -cost, SZ(Graph[from]) - 1 });
    }
    void bfs(lint s) {
        lint V = SZ(Graph);
        level.assign(V, -1);
        queue<lint> que;
        que.push(s);
        level[s] = 0;
        while (!que.empty()) {
            lint v = que.front(); que.pop();
            REP(i, SZ(Graph[v])) {
                edge& e = Graph[v][i];
                if (e.cap > 0 && level[e.to] < 0) {
                    level[e.to] = level[v] + 1;
                    que.push(e.to);
                }
            }
        }
    }
    flow_t dfs(lint v, lint t, flow_t f) {
        if (v == t) return f;
        for (lint& i = iter[v]; i < SZ(Graph[v]); i++) {
            edge& e = Graph[v][i];
            if (e.cap > 0 && level[v] < level[e.to]) {
                flow_t d = dfs(e.to, t, min(f, e.cap));
                if (d > 0) {
                    e.cap -= d;
                    Graph[e.to][e.rev].cap += d;
                    return d;
                }
            }
        }
        return 0;
    }
    flow_t max_flow(lint s, lint t) {
        flow_t flow = 0;
        lint V = SZ(Graph);
        for (;;) {
            bfs(s);
            if (level[t] < 0) return flow;
            iter.assign(V, 0);
            flow_t f;
            while ((f = dfs(s, t, INF)) > 0) {
                flow += f;
            }
        }
    }
    lint min_cost_flow(lint s, lint t, lint f) {
        cost_t res = 0;
        lint V = SZ(Graph);
        potential.assign(V, 0);
        prevv.assign(V, -1);
        preve.assign(V, -1);
        while (f > 0) {
            priority_queue<pair<cost_t, lint>, vector<pair<cost_t, lint> >, greater<pair<cost_t, lint> > > que;
            min_cost.assign(V, INF);
            min_cost[s] = 0;
            que.push({ 0, s });
            while (!que.empty()) {
                pair<cost_t, lint> p = que.top(); que.pop();
                lint v = p.second;
                if (min_cost[v] < p.first) continue;
                REP(i, SZ(Graph[v])) {
                    edge& e = Graph[v][i];
                    cost_t nextCost = min_cost[v] + e.cost + potential[v] - potential[e.to];
                    if (e.cap > 0 && min_cost[e.to] > nextCost) {
                        min_cost[e.to] = nextCost;
                        prevv[e.to] = v;
                        preve[e.to] = i;
                        que.push({ min_cost[e.to], e.to });
                    }
                }
            }
            if (min_cost[t] == INF) {
                return -1;
            }
            REP(v, V) potential[v] += min_cost[v];
            flow_t addflow = f;
            for (lint v = t; v != s; v = prevv[v]) {
                addflow = min(addflow, Graph[prevv[v]][preve[v]].cap);
            }
            f -= addflow;
            res += addflow * potential[t];
            for (lint v = t; v != s; v = prevv[v]) {
                edge& e = Graph[prevv[v]][preve[v]];
                e.cap -= addflow;
                Graph[v][e.rev].cap += addflow;
            }
        }
        return res;
    }
};
lint H, W;
char char_map[50][50];
int main() {
    cin.tie(0); ios_base::sync_with_stdio(false);
    cin >> H >> W;
    lint s = H * W, t = s + 1;
    Flow<lint, lint> g(t + 1);
    lint white_cnt = 0, black_cnt = 0;
    REP(i, H) {
        REP(j, W) {
            cin >> char_map[i][j];
            if (char_map[i][j] == 'b') black_cnt++;
            else if(char_map[i][j] == 'w') white_cnt++;
        }
    }
    REP(i, H) {
        REP(j, W) {
            lint idx = i * W + j;
            if (char_map[i][j] == 'b') {
                g.add_edge(idx, t, 1);
            }
            if (char_map[i][j] == 'w') {
                g.add_edge(s, idx, 1);
                lint dx[4] = { 0, 1, 0, -1 }, dy[4] = { 1, 0, -1, 0 };
                REP(k, 4) {
                    lint ny = i + dy[k], nx = j + dx[k];
                    if (nx >= 0 && ny >= 0 && nx < W && ny < H && char_map[ny][nx] == 'b') {
                        g.add_edge(idx, ny * W + nx, 1);
                    }
                }
            }
        }
    }
    lint match = g.max_flow(s, t);
    white_cnt -= match; black_cnt -= match;
    lint unmatch = min(white_cnt, black_cnt);
    white_cnt -= unmatch; black_cnt -= unmatch;
    cout << match * 100 + unmatch * 10 + white_cnt + black_cnt << endl;
}
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