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답안 #253715

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
253715 2020-07-28T14:57:11 Z rqi Cities (BOI16_cities) C++14
100 / 100
 4124 ms 56612 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

const int mx = 100005;
const int MAXK = 5;
vector<pair<int, ll>> adj[mx];
ll dist[1<<MAXK][mx];
int cities[MAXK];

int main() {
    setIO();
    int n, k, m;
    cin >> n >> k >> m;
    for(int i = 0; i < k; i++){
        cin >> cities[i];
    }
    for(int i = 0; i < m; i++){
        int a, b;
        ll c;
        cin >> a >> b >> c;
        adj[a].pb(mp(b, c));
        adj[b].pb(mp(a, c));
    }

    for(int i = 0; i < (1<<k); i++){
        for(int j = 0; j < mx; j++){
            dist[i][j] = INF;
        }
    }

    for(int i = 1; i < (1<<k); i++){ //generate dist[i]
        int used = 0;
        for(int j = 1; j < (1<<k); j++){
            int s1 = j;
            int s2 = 0;
            bool works = 1;
            for(int b = 0; b < k; b++){
                bool ini = (i>>b)&1;
                bool inj = (j>>b)&1;
                if(!ini && inj){
                    works = 0;
                    break;
                }
                else if(ini && !inj){
                    s2+=(1<<b);
                }
            }
            if(s2 == 0) works = 0;
            if(!works) continue;
            used++;

            for(int ind = 1; ind <= n; ind++){
                //if(i == 5 && ind == 2) dbg(s1, s2, dist[s1][ind], dist[s2][ind]);
                ckmin(dist[i][ind], dist[s1][ind]+dist[s2][ind]);
            }
        }
        //dbg(i, used);
        if(used == 0){
            for(int j = 0; j < k; j++){
                if(((i>>j)&1) == 1){
                    dist[1<<j][cities[j]] = 0;
                    // if(i == 1){
                    //     dbg(j, 1<<j, cities[j]);
                    // }
                    break;
                }
            }
        }

        priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;

        for(int ind = 1; ind <= n; ind++){
            pq.push(mp(dist[i][ind], ind));
            dist[i][ind] = INF;
        }
        while(sz(pq)){
            pair<ll, int> p = pq.top();
            pq.pop();
            if(dist[i][p.s] <= p.f) continue;
            dist[i][p.s] = p.f;
            for(auto u: adj[p.s]){
                pq.push(mp(p.f+u.s, u.f));
            }
        }
    }

    ll ans = INF;
    for(int ind = 1; ind <= n; ind++){
        ckmin(ans, dist[(1<<k)-1][ind]);
    }

    // for(int i = 1; i < (1<<k); i++){
    //     for(int j = 1; j <= n; j++){
    //         dbg(i, j, dist[i][j]);
    //     }
    // }

    ps(ans);

    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message

cities.cpp: In function 'void setIn(std::__cxx11::string)':
cities.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
cities.cpp: In function 'void setOut(std::__cxx11::string)':
cities.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 5760 KB Output is correct
2 Correct 3 ms 5760 KB Output is correct
3 Correct 5 ms 8960 KB Output is correct
4 Correct 8 ms 15232 KB Output is correct
5 Correct 15 ms 27776 KB Output is correct

Subtask #2
14.0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1037 ms 35860 KB Output is correct
2 Correct 1010 ms 35328 KB Output is correct
3 Correct 436 ms 20176 KB Output is correct
4 Correct 663 ms 35660 KB Output is correct
5 Correct 536 ms 32776 KB Output is correct
6 Correct 347 ms 32408 KB Output is correct
7 Correct 10 ms 9216 KB Output is correct
8 Correct 6 ms 6016 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 15488 KB Output is correct
2 Correct 19 ms 15532 KB Output is correct
3 Correct 13 ms 15360 KB Output is correct
4 Correct 17 ms 15488 KB Output is correct

Subtask #4
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2190 ms 42280 KB Output is correct
2 Correct 2069 ms 41576 KB Output is correct
3 Correct 963 ms 26388 KB Output is correct
4 Correct 1720 ms 42660 KB Output is correct
5 Correct 1413 ms 41704 KB Output is correct
6 Correct 1410 ms 44136 KB Output is correct

Subtask #5
26.0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4091 ms 54852 KB Output is correct
2 Correct 4089 ms 54720 KB Output is correct
3 Correct 4124 ms 54120 KB Output is correct
4 Correct 1947 ms 39168 KB Output is correct
5 Correct 3469 ms 55260 KB Output is correct
6 Correct 2815 ms 54304 KB Output is correct
7 Correct 2728 ms 56612 KB Output is correct