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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#873598#4809. Maximum RangesunkuangzhengWA 42ms51512kbC++208.0kb2025-01-26 18:13:432025-01-26 18:13:44

Judging History

你现在查看的是最新测评结果

  • [2025-01-26 18:13:44]
  • 评测
  • 测评结果:WA
  • 用时:42ms
  • 内存:51512kb
  • [2025-01-26 18:13:43]
  • 提交

answer

/**
 *    author: sunkuangzheng
 *    created: 26.01.2025 17:32:53
**/
#include<bits/stdc++.h>
#ifdef DEBUG_LOCAL
#include <mydebug/debug.h>
#endif

#include <algorithm>

#include <vector>

namespace atcoder {

namespace internal {

template <class T> struct simple_queue {
    std::vector<T> payload;
    int pos = 0;
    void reserve(int n) { payload.reserve(n); }
    int size() const { return int(payload.size()) - pos; }
    bool empty() const { return pos == int(payload.size()); }
    void push(const T& t) { payload.push_back(t); }
    T& front() { return payload[pos]; }
    void clear() {
        payload.clear();
        pos = 0;
    }
    void pop() { pos++; }
};

}  // namespace internal

}  // namespace atcoder

#include <cassert>
#include <limits>
#include <queue>
#include <vector>

namespace atcoder {

template <class Cap> struct mf_graph {
  public:
    mf_graph() : _n(0) {}
    mf_graph(int n) : _n(n), g(n) {}

    int add_edge(int from, int to, Cap cap) {
        assert(0 <= from && from < _n);
        assert(0 <= to && to < _n);
        assert(0 <= cap);
        int m = int(pos.size());
        pos.push_back({from, int(g[from].size())});
        int from_id = int(g[from].size());
        int to_id = int(g[to].size());
        if (from == to) to_id++;
        g[from].push_back(_edge{to, to_id, cap});
        g[to].push_back(_edge{from, from_id, 0});
        return m;
    }

    struct edge {
        int from, to;
        Cap cap, flow;
    };

    edge get_edge(int i) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        auto _e = g[pos[i].first][pos[i].second];
        auto _re = g[_e.to][_e.rev];
        return edge{pos[i].first, _e.to, _e.cap + _re.cap, _re.cap};
    }
    std::vector<edge> edges() {
        int m = int(pos.size());
        std::vector<edge> result;
        for (int i = 0; i < m; i++) {
            result.push_back(get_edge(i));
        }
        return result;
    }
    void change_edge(int i, Cap new_cap, Cap new_flow) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        assert(0 <= new_flow && new_flow <= new_cap);
        auto& _e = g[pos[i].first][pos[i].second];
        auto& _re = g[_e.to][_e.rev];
        _e.cap = new_cap - new_flow;
        _re.cap = new_flow;
    }

    Cap flow(int s, int t) {
        return flow(s, t, std::numeric_limits<Cap>::max());
    }
    Cap flow(int s, int t, Cap flow_limit) {
        assert(0 <= s && s < _n);
        assert(0 <= t && t < _n);
        assert(s != t);

        std::vector<int> level(_n), iter(_n);
        internal::simple_queue<int> que;

        auto bfs = [&]() {
            std::fill(level.begin(), level.end(), -1);
            level[s] = 0;
            que.clear();
            que.push(s);
            while (!que.empty()) {
                int v = que.front();
                que.pop();
                for (auto e : g[v]) {
                    if (e.cap == 0 || level[e.to] >= 0) continue;
                    level[e.to] = level[v] + 1;
                    if (e.to == t) return;
                    que.push(e.to);
                }
            }
        };
        auto dfs = [&](auto self, int v, Cap up) {
            if (v == s) return up;
            Cap res = 0;
            int level_v = level[v];
            for (int& i = iter[v]; i < int(g[v].size()); i++) {
                _edge& e = g[v][i];
                if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;
                Cap d =
                    self(self, e.to, std::min(up - res, g[e.to][e.rev].cap));
                if (d <= 0) continue;
                g[v][i].cap += d;
                g[e.to][e.rev].cap -= d;
                res += d;
                if (res == up) break;
            }
            return res;
        };

        Cap flow = 0;
        while (flow < flow_limit) {
            bfs();
            if (level[t] == -1) break;
            std::fill(iter.begin(), iter.end(), 0);
            while (flow < flow_limit) {
                Cap f = dfs(dfs, t, flow_limit - flow);
                if (!f) break;
                flow += f;
            }
        }
        return flow;
    }

    std::vector<bool> min_cut(int s) {
        std::vector<bool> visited(_n);
        internal::simple_queue<int> que;
        que.push(s);
        while (!que.empty()) {
            int p = que.front();
            que.pop();
            visited[p] = true;
            for (auto e : g[p]) {
                if (e.cap && !visited[e.to]) {
                    visited[e.to] = true;
                    que.push(e.to);
                }
            }
        }
        return visited;
    }

  private:
    int _n;
    struct _edge {
        int to, rev;
        Cap cap;
    };
    std::vector<std::pair<int, int>> pos;
    std::vector<std::vector<_edge>> g;
};

}  // namespace atcoder

using ll = long long;
const int N = 5e5+5;
using namespace std;
int T,tt,tp,ti,n,m,u,v,w,dfn[N],low[N],st[N],vis[N],be[N],mx[N],mn[N],cnt; 
vector<pair<int,int>> g[N],ge[N]; map<int,short> p[N]; vector<int> sta;
void cmx(int &x,int y){x = max(x,y);}
void cmn(int &x,int y){x = min(x,y);}
void dfs(int u,int f){
    dfn[u] = low[u] = ++ti,vis[u] = 1,st[++tp] = u;
    for(auto [v,w] : g[u]) if(v != f){
        if(!dfn[v]) dfs(v,u),low[u] = min(low[u],low[v]);
        else if(vis[v]) low[u] = min(low[u],dfn[v]);
    }if(low[u] == dfn[u])
        for(++tt;;) if(vis[st[tp]] = 0,be[st[tp]] = tt,st[tp --] == u) break;
}void dfs(int u){
    sta.push_back(u);
    for(auto [v,id] : ge[u]) if(!vis[id]) vis[id] = 1,dfs(v); 
}int main(){
    ios::sync_with_stdio(0),cin.tie(0);
    cin >> n >> m;
    for(int i = 1;i <= m;i ++) cin >> u >> v >> w,
        g[u].emplace_back(v,w),g[v].emplace_back(u,w);
    dfs(1,0);
    for(int i = 0;i <= tt;i ++) mx[i] = -1e9 - 1,mn[i] = 1e9 + 1;
    for(int i = 1;i <= n;i ++)
        for(auto [v,w] : g[i]) if(be[i] == be[v])
            cmx(mx[be[i]],w),cmn(mn[be[i]],w);
    int id = 0;
    for(int i = 1;i <= tt;i ++) if(mx[i] - mn[i] > mx[id] - mn[id]) id = i;
    cout << mx[id] - mn[id] << "\n"; 
    int u = 0,v = 0,U = 0,V = 0;
    vector<pair<int,int>> gr(1);
    for(int i = 1;i <= n;i ++) for(auto [j,w] : g[i])
        if(be[i] == id && be[j] == id && w == mx[id]) u = i,v = j;
    for(int i = 1;i <= n;i ++) for(auto [j,w] : g[i])
        if(be[i] == id && be[j] == id && w == mn[id] && minmax(i,j) != minmax(u,v)) 
            U = i,V = j;
    for(int i = 1;i <= n;i ++) for(auto [j,w] : g[i]) 
        if(be[i] == id && be[j] == id && i < j) gr.emplace_back(i,j);
    int k = gr.size() - 1,i0 = 0,i1 = 0;
    atcoder::mf_graph<int> G(n + 2 + 2 * k);
    int s = 0,t = n + 1 + 2 * k;
    for(int i = 1;i <= k;i ++){
        auto [x,y] = gr[i];
        if(minmax(x,y) == minmax(u,v)){
            G.add_edge(s,i+n,2),i0 = i,
            G.add_edge(i+n,x,1),G.add_edge(i+n,y,1);
        }else if(minmax(x,y) == minmax(U,V)){
            G.add_edge(i+n,t,2),i1 = i,
            G.add_edge(x,i+n,1),G.add_edge(y,i+n,1);
        }else{
            G.add_edge(x,i+n,1),G.add_edge(y,i+n,1);
            G.add_edge(i+n,i+n+k,1);
            G.add_edge(i+n+k,x,1),G.add_edge(i+n+k,y,1);
        }
    }assert(i0 && i1);
    int res = G.flow(s,t);
    assert(res == 2);
    memset(vis,0,sizeof(vis));
    auto E = G.edges();
    for(auto [u,v,c,f] : E) if(f)
        if(u <= n && v <= n + k) p[u][v - n] |= 1;
        else if(v <= n && u <= n + k) p[v][u - k] |= 2;
    for(auto [u,v,c,f] : E) if(f && u > n && u <= n + k && v > n + k && v <= n + 2 * k){
        int id = u - n;
        auto [u,v] = gr[id];
        if(p[u][id] != 3 && p[v][id] != 3) ge[u].emplace_back(v,cnt),ge[v].emplace_back(u,cnt ++);
    }ge[u].emplace_back(v,cnt),ge[v].emplace_back(u,cnt ++);
    ge[U].emplace_back(V,cnt),ge[V].emplace_back(U,cnt ++);
    cout << cnt << "\n";
    dfs(U);
    reverse(sta.begin(),sta.end()),sta.pop_back();
    for(int u : sta) cout << u << " ";
    cout << "\n";
}

详细

Test #1:

score: 100
Accepted
time: 5ms
memory: 42880kb

input:

5 7
1 2 1
1 3 -2
2 3 1
3 4 3
4 5 1
1 5 -1
2 5 2

output:

5
4
3 1 5 4 

result:

ok ok

Test #2:

score: 0
Accepted
time: 38ms
memory: 51388kb

input:

99997 100000
12238 99016 352755196
99016 25485 -412473602
25485 2440 991507552
2440 31171 -181894654
36970 2440 -800167579
2440 41865 -148191946
96629 31171 847888506
36970 95740 395546542
27992 2440 647886610
99016 29557 369124914
80795 27992 -673871966
36970 3509 573208857
57672 29557 874406776
41...

output:

1959330954
37
95092 31171 2440 25485 99016 29557 57672 69259 68883 44442 4697 96048 94991 86274 74677 92617 86665 76022 72089 22074 96230 87712 51491 72825 3463 84407 67966 89628 84997 54073 68523 30288 88289 37694 96778 46301 34883 

result:

ok ok

Test #3:

score: 0
Accepted
time: 41ms
memory: 50576kb

input:

99997 100000
41884 21178 -431811360
41884 42699 -450057006
36523 21178 582079730
21178 96679 615552614
63637 21178 498974417
96679 5108 235820276
75058 41884 220112636
35148 42699 589595309
36523 18002 -637739861
65854 5108 -312755792
45137 41884 -511118771
5108 31311 554050951
25335 35148 -28341059...

output:

1968439328
40
70298 33264 26071 90144 25926 52252 51434 69337 7577 5108 50088 6204 28694 41126 87303 83047 26981 54901 59612 14678 35287 78274 18331 89860 71024 99686 98098 23692 87673 42699 41884 45137 85192 38202 83711 83919 55330 71151 98733 99716 

result:

ok ok

Test #4:

score: 0
Accepted
time: 41ms
memory: 51512kb

input:

99984 99999
33974 29867 335681778
33974 87468 348956829
83048 87468 320849805
29867 69456 -424530698
72457 69456 -950650074
53838 83048 755969166
85914 69456 569454441
51728 87468 -202158773
15970 29867 -865071002
15970 94894 697607001
94894 74694 616318126
33974 11496 -89287579
53838 34365 -6577379...

output:

1985932414
36
92249 11395 303 46598 61993 55857 79605 58540 57640 55808 85914 75496 32897 79841 13570 35807 50114 80694 78849 28078 91542 83656 97838 70238 5449 75902 51728 87468 83048 53838 29864 76013 1652 83298 23026 27866 

result:

ok ok

Test #5:

score: -100
Wrong Answer
time: 42ms
memory: 48912kb

input:

99988 99992
8584 11873 -811540160
68064 11873 -930246087
11873 60056 916668870
68064 82193 -859062523
60056 75072 790866030
27767 75072 357619485
75072 78221 411650300
39636 82193 264106928
6675 60056 933851261
71747 78221 -508471038
11873 92771 -665232168
34402 27767 -906494982
11873 42714 63734230...

output:

1932268861
32
93559 75593 83884 20678 16385 62720 25891 75176 34179 64174 38274 8778 99809 28745 89787 32701 6675 60056 75072 91957 3186 29873 5185 88236 50628 2518 83283 23798 89787 8975 26922 21107 

result:

wrong answer Edge 28745-89787 does not appear in original graph