compro-library

This documentation is automatically generated by online-judge-tools/verification-helper

View the Project on GitHub ningenMe/compro-library

:heavy_check_mark: test/graph/MinimumUndirectedClosedCircuit.test.cpp

Depends on

Code

#define PROBLEM "https://yukicoder.me/problems/no/13"

#include <vector>
#include <iostream>
#include <algorithm>
#include <cassert>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <array>

using namespace std;
#include "../../lib/40-graph/Graph.cpp"
#include "../../lib/15-queue/RadixHeap.cpp"
#include "../../lib/40-graph/MinimumUndirectedClosedCircuit.cpp"

int main(){
    cin.tie(0);ios::sync_with_stdio(false);
    int W,H; cin >> W >> H;
    Graph<int> g(H,W);
    vector<int> a(W),b(W);
    {
        for(int j=0;j  <W;++j) cin >> a[j];
        for(int j=0;j+1<W;++j) if(a[j]==a[j+1]) g.make_bidirectional_edge({0,j},{0,j+1},1);        
    }
    for(int i=1;i<H;++i) {
        b=a;
        for(int j=0;j  <W;++j) cin >> a[j];
        for(int j=0;j  <W;++j) if(b[j]==a[j]) g.make_bidirectional_edge({i,j},{i-1,j},1);
        for(int j=0;j+1<W;++j) if(a[j]==a[j+1]) g.make_bidirectional_edge({i,j},{i,j+1},1);
    }
    int inf = 12345678;
    MinimumUndirectedClosedCircuit<int> mucc(g,inf);
    int flg = 0;
    for(int i=0;i<H;++i) for(int j=0;j<W;++j) {
        int sz = mucc.solve(g.idx({i,j}));
        if(sz < inf) flg = 1;
    }
    cout << (flg?"possible":"impossible") << endl;
	return 0;
}
#line 1 "test/graph/MinimumUndirectedClosedCircuit.test.cpp"
#define PROBLEM "https://yukicoder.me/problems/no/13"

#include <vector>
#include <iostream>
#include <algorithm>
#include <cassert>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <array>

using namespace std;
#line 1 "lib/40-graph/Graph.cpp"
/*
 * @title Graph
 * @docs md/graph/Graph.md
 */
template<class T> class Graph{
private:
    const size_t N,H,W;
public:
    vector<vector<pair<size_t,T>>> edges;
    Graph(const size_t N):H(-1),W(-1),N(N), edges(N) {}
    Graph(const size_t H, const size_t W):H(H),W(W),N(H*W), edges(H*W) {}
    inline void make_edge(size_t from, size_t to, T w) {
        edges[from].emplace_back(to,w);
    }
    //{from_y,from_x} -> {to_y,to_x} 
    inline void make_edge(pair<size_t,size_t> from, pair<size_t,size_t> to, T w) {
        make_edge(from.first*W+from.second,to.first*W+to.second,w);
    }
    inline void make_bidirectional_edge(size_t from, size_t to, T w) {
        make_edge(from,to,w);
        make_edge(to,from,w);
    }
    inline void make_bidirectional_edge(pair<size_t,size_t> from, pair<size_t,size_t> to, T w) {
        make_edge(from.first*W+from.second,to.first*W+to.second,w);
        make_edge(to.first*W+to.second,from.first*W+from.second,w);
    }
    inline size_t size(){return N;}
    inline size_t idx(pair<size_t,size_t> yx){return yx.first*W+yx.second;}
};
#line 1 "lib/15-queue/RadixHeap.cpp"

/*
 * @title RadixHeap - 非負整数heap
 * @docs md/queue/RadixHeap.md
 */
template<class T, class Key = unsigned long long> class RadixHeap{
    using TypeNode = pair<Key, T>;
    template<class InnerKey, class ZZ=InnerKey> class Inner{};
    template<class InnerKey> class Inner<InnerKey, unsigned long long>{
        array<vector<TypeNode>,65> vq;
        unsigned long long size_num;
        TypeNode last;
        inline int bit(unsigned long long a) { return a ? 64 - __builtin_clzll(a) : 0;}
    public:
        Inner(T mini) : size_num(0), last(make_pair(0, mini)) {}
        inline bool empty() { return size_num == 0; }
        inline size_t size(){ return size_num; }
        inline void push(TypeNode x){ ++size_num; vq[bit(x.first^last.first)].push_back(x);}
        inline void emplace(unsigned long long key,T val){ ++size_num; vq[bit(key^last.first)].emplace_back(key,val);}
        inline TypeNode pop() {
            if(vq[0].empty()) {
                int i = 1;
                while(vq[i].empty()) ++i;
                last = *min_element(vq[i].begin(),vq[i].end());
                for(auto &p : vq[i]) vq[bit(p.first ^ last.first)].push_back(p);
                vq[i].clear();
            }
            --size_num;
            auto res = vq[0].back(); vq[0].pop_back();
            return res;
        }
    };
    template<class InnerKey> class Inner<InnerKey, unsigned int>{
        array<vector<TypeNode>,33> vq;
        unsigned int size_num;
        TypeNode last;
        inline int bit(unsigned int a) { return a ? 32 - __builtin_clz(a) : 0;}
    public:
        Inner(T mini) : size_num(0), last(make_pair(0, mini)) {}
        inline bool empty() { return size_num == 0; }
        inline size_t size(){ return size_num; }
        inline void push(TypeNode x){ ++size_num; vq[bit(x.first^last.first)].push_back(x);}
        inline void emplace(unsigned int key,T val){ ++size_num; vq[bit(key^last.first)].emplace_back(key,val);}
        inline TypeNode pop() {
            if(vq[0].empty()) {
                int i = 1;
                while(vq[i].empty()) ++i;
                last = *min_element(vq[i].begin(),vq[i].end());
                for(auto &p : vq[i]) vq[bit(p.first ^ last.first)].push_back(p);
                vq[i].clear();
            }
            --size_num;
            auto res = vq[0].back(); vq[0].pop_back();
            return res;
        }
    };
    Inner<Key,Key> inner;
public:
    RadixHeap(T mini) : inner(mini) {}
    inline bool empty() { return inner.empty();}
    inline size_t size(){ return inner.size();}
    inline void push(TypeNode x){ inner.push(x);}
    inline void emplace(unsigned long long key,T val){ inner.emplace(key,val);}
    inline TypeNode pop() { return inner.pop(); }
};
#line 1 "lib/40-graph/MinimumUndirectedClosedCircuit.cpp"

/*
 * @title MinimumUndirectedClosedCircuit - 無向グラフの最小閉路検出
 * @docs md/graph/MinimumUndirectedClosedCircuit.md
 */
template<class T> class MinimumUndirectedClosedCircuit {
    //Tは整数型のみ
    static_assert(std::is_integral<T>::value, "template parameter T must be integral type");
    Graph<T> graph;
    vector<T> dist;
    vector<int> parent,label;
    size_t N;
    T inf;
    int last_l,last_r,root;
private:
    void solve_impl() {
        RadixHeap<int, unsigned int> q(0);
        q.push({0,root});
        dist[root] = 0;
        while (q.size()) {
            auto top =  q.pop();
            size_t curr = top.second;
            if(top.first > dist[curr]) continue;
            for(auto& edge:graph.edges[curr]){
                size_t next = edge.first;
                T w  = edge.second;
                if(parent[curr] == next) continue;
                if(dist[next] > dist[curr] + w) {
                    dist[next]   = dist[curr] + w;
                    parent[next] = curr;
                    label[next]  = (curr==root?next:label[curr]);
                    q.push({dist[next],next});
                }
            }
        }
    }
    T solve_cycle() {
        T mini = inf;
        last_l=-1,last_r=-1;
        for(int l=0;l<N;++l) {
            if(l==root) continue;
            for(auto& edge:graph.edges[l]){
                int r = edge.first;
                T   w = edge.second;
                if(mini <= dist[l] + dist[r] + w) continue;
                if( (r==root && l!=label[l]) || (r!=root && label[l]!=label[r]) ) {
                    mini = dist[l] + dist[r] + w;
                    last_l = l;
                    last_r = r;
                }
            }
        }
        return mini;
    }
public:
    MinimumUndirectedClosedCircuit(Graph<T>& graph, T inf)
            : graph(graph),N(graph.size()),dist(graph.size()),parent(graph.size()),label(graph.size()),inf(inf) {
    }
    //rootを含む最小閉路の集合を返す O(NlogN) 閉路がないときは空集合
    inline T solve(size_t rt){
        root = rt;
        //初期化
        for(int i = 0; i < N; ++i) dist[i] = inf, parent[i] = -1;
        solve_impl();
        T mini=solve_cycle();
        return mini;
    }
    //復元
    vector<int> restore() {
        stack<int> s;
        queue<int> q;
        vector<int> res;
        if(last_l != -1 && last_r != -1){
            for(int curr = last_l; curr != -1; curr = parent[curr]) s.push(curr);
            for(int curr = last_r; curr != root; curr = parent[curr]) q.push(curr);
            while(s.size()) res.push_back(s.top())  ,s.pop();
            while(q.size()) res.push_back(q.front()),q.pop();
        }
        return res;
    }
};
#line 17 "test/graph/MinimumUndirectedClosedCircuit.test.cpp"

int main(){
    cin.tie(0);ios::sync_with_stdio(false);
    int W,H; cin >> W >> H;
    Graph<int> g(H,W);
    vector<int> a(W),b(W);
    {
        for(int j=0;j  <W;++j) cin >> a[j];
        for(int j=0;j+1<W;++j) if(a[j]==a[j+1]) g.make_bidirectional_edge({0,j},{0,j+1},1);        
    }
    for(int i=1;i<H;++i) {
        b=a;
        for(int j=0;j  <W;++j) cin >> a[j];
        for(int j=0;j  <W;++j) if(b[j]==a[j]) g.make_bidirectional_edge({i,j},{i-1,j},1);
        for(int j=0;j+1<W;++j) if(a[j]==a[j+1]) g.make_bidirectional_edge({i,j},{i,j+1},1);
    }
    int inf = 12345678;
    MinimumUndirectedClosedCircuit<int> mucc(g,inf);
    int flg = 0;
    for(int i=0;i<H;++i) for(int j=0;j<W;++j) {
        int sz = mucc.solve(g.idx({i,j}));
        if(sz < inf) flg = 1;
    }
    cout << (flg?"possible":"impossible") << endl;
	return 0;
}
Back to top page