Submission #62757

#	Time	Username	Problem	Language	Result	Execution time	Memory
62757		Benq	Travelling Merchant (APIO17_merchant)	C++11	100 / 100	142 ms	13548 KiB

merchant

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

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

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

template<int SZ> struct Topo {
    int N, in[SZ];
    vi res, adj[SZ];
    
    void addEdge(int x, int y) {
    	adj[x].pb(y), in[y] ++;
    }
    
    void sort() {
        queue<int> todo;
        F0R(i,N) if (in[i] == 0) todo.push(i);
        while (sz(todo)) {
            int x = todo.front(); todo.pop();
            res.pb(x);
            for (int i: adj[x]) {
                in[i] --;
                if (!in[i]) todo.push(i);
            }
        }
    }
};

int N,M,K,B[100][1000],S[100][1000];
int prof[100][100],dist[100][100];
array<ll,100> tmp;
vi adj[100];

bool ok(int mid) {
    F0R(i,N) {
        adj[i].clear();
        tmp[i] = 0;
    }
    F0R(i,N) {
        auto TMP = tmp;
        F0R(j,N) F0R(k,N) if (j != k && dist[j][k] != MOD) 
            TMP[k] = max(TMP[k],tmp[j]+prof[j][k]-(ll)dist[j][k]*mid);
        tmp = TMP;
    }
    Topo<100> T = Topo<100>(); T.N = N;
    F0R(j,N) F0R(k,N) if (j != k && dist[j][k] != MOD) {
        ll d = tmp[j]+prof[j][k]-(ll)dist[j][k]*mid;
        if (tmp[k] < d) return 1;
        else if (tmp[k] == d) T.addEdge(j,k);
    }
    T.sort();
    return sz(T.res) != N;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> M >> K;
    F0R(i,N) F0R(j,K) cin >> B[i][j] >> S[i][j];
    F0R(i,N) F0R(j,N) if (i != j) dist[i][j] = MOD;
    F0R(i,M) {
        int V,W,T; cin >> V >> W >> T; V--, W--;
        dist[V][W] = min(dist[V][W],T);
    }
    F0R(k,N) F0R(i,N) F0R(j,N) dist[i][j] = min(dist[i][j],dist[i][k]+dist[k][j]);
    F0R(i,N) F0R(j,N) {
        F0R(k,K) if (B[i][k] != -1 && S[j][k] != -1)
            prof[i][j] = max(prof[i][j],S[j][k]-B[i][k]);
        // cout << "AH " << i << " " << j << " " << prof[i][j] << " " << dist[i][j] << "\n";
    }
    
    ok(6);
    int lo = 0, hi = MOD;
    while (lo < hi) {
        int mid = (lo+hi+1)/2;
        if (ok(mid)) lo = mid;
        else hi = mid-1;
    }
    cout << lo;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

• Subtask 1: 12 / 12
• Subtask 2: 21 / 21
• Subtask 3: 33 / 33
• Subtask 4: 34 / 34