#790984 (C++17) No.20 砂漠のオアシス

• 問題: No.20 砂漠のオアシス
• ユーザー: raven7959
• 提出日時: 2022-08-21 10:43:03
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 27 ms / 5,000 ms
• コード長: 5,926 bytes
• コンパイル時間: 2,474 ms
• コンパイル使用メモリ: 224,740 KB
• 実行使用メモリ: 8,600 KB
• 最終ジャッジ日時: 2024-10-10 03:43:11
• 合計ジャッジ時間: 3,721 ms
• ジャッジサーバーID （参考情報）: judge5 / judge1

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 6,820 KB
testcase_01	AC	2 ms; 6,820 KB
testcase_02	AC	2 ms; 6,820 KB
testcase_03	AC	2 ms; 6,816 KB
testcase_04	AC	2 ms; 6,816 KB
testcase_05	AC	21 ms; 7,680 KB
testcase_06	AC	26 ms; 8,588 KB
testcase_07	AC	26 ms; 8,596 KB
testcase_08	AC	19 ms; 8,320 KB
testcase_09	AC	27 ms; 8,600 KB
testcase_10	AC	2 ms; 6,816 KB
testcase_11	AC	2 ms; 6,816 KB
testcase_12	AC	3 ms; 6,820 KB
testcase_13	AC	3 ms; 6,816 KB
testcase_14	AC	4 ms; 6,816 KB
testcase_15	AC	3 ms; 6,816 KB
testcase_16	AC	6 ms; 6,816 KB
testcase_17	AC	5 ms; 6,820 KB
testcase_18	AC	6 ms; 6,820 KB
testcase_19	AC	6 ms; 6,816 KB
testcase_20	AC	3 ms; 6,816 KB

ソースコード

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,fma,abm,mmx,avx,avx2")
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) int(x.size())
#define yn(joken) cout<<((joken) ? "Yes" : "No")<<"\n"
#define YN(joken) cout<<((joken) ? "YES" : "NO")<<"\n"
using namespace std;
using ll = long long;
using vi = vector<int>;
using vl = vector<ll>;
using vs = vector<string>;
using vc = vector<char>;
using vd = vector<double>;
using vld = vector<long double>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
using vvs = vector<vector<string>>;
using vvc = vector<vector<char>>;
using vvd = vector<vector<double>>;
using vvld = vector<vector<long double>>;
using vvvi = vector<vector<vector<int>>>;
using vvvl = vector<vector<vector<ll>>>;
using vvvvi = vector<vector<vector<vector<int>>>>;
using vvvvl = vector<vector<vector<vector<ll>>>>;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
const int INF = 1e9;
const ll LINF = 2e18;
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;
}
bool ispow2(int i) { return i && (i & -i) == i; }
bool ispow2(ll i) { return i && (i & -i) == i; }
template <class T>
vector<T> make_vec(size_t a) {
    return vector<T>(a);
}
template <class T, class... Ts>
auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}
template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) {
        is >> v[i];
    }
    return is;
}
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) {
        os << v[i];
        if (i < int(v.size()) - 1) os << ' ';
    }
    return os;
}

static uint32_t RandXor(){
    static uint32_t x=123456789;
    static uint32_t y=362436069;
    static uint32_t z=521288629;
    static uint32_t w=88675123;
    uint32_t t;
 
    t=x^(x<<11);
    x=y; y=z; z=w;
    return w=(w^(w>>19))^(t^(t>>8));
}

static double Rand01(){
    return (RandXor()+0.5)*(1.0/UINT_MAX);
}

template <typename T = int>
struct Edge{
    int from, to;
    T cost;
    int idx;
    Edge() = default;
    Edge(int from, int to, T cost = 1, int idx = -1) : from(from), to(to), cost(cost), idx(idx) {}
    operator int() const { return to; }
};

template <typename T = int>
struct Graph{
    vector<vector<Edge<T>>> g;
    int es;
    Graph() = default;
    explicit Graph(int n) : g(n), es(0) {}
    size_t size() const{
        return g.size();
    }

    void add_directed_edge(int from, int to, T cost = 1){
        g[from].emplace_back(from, to, cost, es++);
    }

    void add_edge(int from, int to, T cost = 1){
        g[from].emplace_back(from, to, cost, es);
        g[to].emplace_back(to, from, cost, es++);
    }

    void read(int M, int padding = -1, bool weighted = false, bool directed = false){
        for (int i = 0; i < M; i++){
            int a, b;
            cin >> a >> b;
            a += padding;
            b += padding;
            T c = T(1);
            if (weighted) cin >> c;
            if (directed) add_directed_edge(a, b, c);
            else add_edge(a, b, c);
        }
    }

    inline vector<Edge<T>> &operator[](const int &k){
        return g[k];
    }

    inline const vector<Edge<T>> &operator[](const int &k) const{
        return g[k];
    }
};

template <typename T = int>
using Edges = vector<Edge<T>>;

// dijkstra(g,start) とする. 返り値は以下の3つ.
// startからの最短距離の配列 dist
// 最短経路でその頂点の前に通る頂点の配列 from (startおよび到達不能頂点では-1)
// 最短経路でその頂点の前に通る辺の辺番号の配列 idx (startおよび到達不能頂点では-1)

template <typename T>
struct ShortestPath{
    vector<T> dist;
    vector<int> from, id;
};

template <typename T>
ShortestPath<T> dijkstra(const Graph<T> &g, int s){
    const auto INF = numeric_limits<T>::max();
    vector<T> dist(g.size(), INF);
    vector<int> from(g.size(), -1), id(g.size(), -1);
    using Pi = pair<T, int>;
    priority_queue<Pi, vector<Pi>, greater<>> que;
    dist[s] = 0;
    que.emplace(dist[s], s);
    while (!que.empty()){
        T cost;
        int idx;
        tie(cost, idx) = que.top();
        que.pop();
        if (dist[idx] < cost) continue;
        for (auto &e : g[idx]){
            auto next_cost = cost + e.cost;
            if (dist[e.to] <= next_cost) continue;
            dist[e.to] = next_cost;
            from[e.to] = idx;
            id[e.to] = e.idx;
            que.emplace(dist[e.to], e.to);
        }
    }
    return {dist, from, id};
}

void solve(){
    int N,V,Y,X;
    cin>>N>>V>>Y>>X;
    X--; Y--;
    vvi F(N,vi(N));
    rep(i,N) cin>>F[i];
    Graph<int> G(N*N);
    auto inside=[&](int x,int y){
        return 0<=x && x<N && 0<=y && y<N;
    };
    vi dx={0,-1,0,1},dy={-1,0,1,0};
    int O=X*N+Y;
    rep(x,N){
        rep(y,N){
            rep(d,4){
                int nx=x+dx[d],ny=y+dy[d];
                if(!inside(nx,ny)) continue;
                G.add_directed_edge(x*N+y,nx*N+ny,F[nx][ny]);
            }
        }
    }
    auto D=dijkstra(G,0).dist;
    if(X==-1 && Y==-1){
        YN(D[N*N-1]<V);
    }
    else{
        if(D[N*N-1]<V){
            cout<<"YES"<<endl;
        }
        else if(D[O]>=V){
            cout<<"NO"<<endl;
        }
        else{
            V=2*(V-D[O]);
            auto D2=dijkstra(G,O).dist;
            YN(D2[N*N-1]<V);
        }
    }
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    solve();
}