Submission #968059

#	Time	Username	Problem	Language	Result	Execution time	Memory
968059		yeediot	Cities (BOI16_cities)	C++17	100 / 100	1659 ms	46220 KiB

cities

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
    int a,b;
    int operator()(const int x)const{
        return a*x+b;
    }
};
bool check(line l1,line l2,line l3){
    return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
const int mxn=1e5+5;
const int inf=1e18;
vector<int>need;
vector<pii>adj[mxn];
int n,k;
int dp[1<<5][mxn];
void dij(int x){
    int st=need[x];
    priority_queue<pii,vector<pii>,greater<pii>>pq;
    for(int i=1;i<=n;i++){
        pq.push({dp[x][i],i});
    }
    while(sz(pq)){
        auto [d,v]=pq.top();
        pq.pop();
        if(d>dp[x][v])continue;
        for(auto [u,l]:adj[v]){
            if(dp[x][v]+l<dp[x][u]){
                dp[x][u]=dp[x][v]+l;
                pq.push({dp[x][u],u});
            }
        }
    }
}
signed main(){
    setio();
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int m;
    cin>>n>>k>>m;
    for(int i=0;i<(1<<k);i++){
        for(int j=0;j<n;j++){
            dp[i][j]=inf;
        }
    }
    for(int i=0;i<k;i++){
        int x;
        cin>>x;
        x--;
        need.pb(x);
        dp[1<<i][x]=0;
    }
    for(int i=0;i<m;i++){
        int a,b,c;
        cin>>a>>b>>c;
        a--;
        b--;
        adj[a].pb({b,c});
        adj[b].pb({a,c});
    }
    for(int i=1;i<(1<<k);i++){
        for(int j=0;j<n;j++){
            for(int h=i;h>0;h=(h-1&i)){
                if((i^h)>h)break;
                chmin(dp[i][j],dp[h][j]+dp[i^h][j]);
            }
        }
        dij(i);
    }
    int ans=inf;
    for(int i=0;i<n;i++){
        chmin(ans,dp[(1<<k)-1][i]);
    }
    cout<<ans<<'\n';
}
 /*
 input:
 
 */















 

Compilation message (stderr)

cities.cpp: In function 'void dij(long long int)':
cities.cpp:61:9: warning: unused variable 'st' [-Wunused-variable]
   61 |     int st=need[x];
      |         ^~
cities.cpp: In function 'int main()':
cities.cpp:106:33: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
  106 |             for(int h=i;h>0;h=(h-1&i)){
      |                                ~^~
cities.cpp: In function 'void setIO(std::string)':
cities.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26