Submission #567447

#	Time	Username	Problem	Language	Result	Execution time	Memory
567447		SavicS	Toll (BOI17_toll)	C++17	100 / 100	314 ms	32528 KiB

toll

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
 
using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ldb;
 
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ldb,ldb> pdd;

#define ff(i,a,b) for(int i = a; i <= b; i++)
#define fb(i,b,a) for(int i = b; i >= a; i--)
#define trav(a,x) for (auto& a : x)
 
#define sz(a) (int)(a).size()
#define fi first
#define se second
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// os.order_of_key(k) the number of elements in the os less than k
// *os.find_by_order(k)  print the k-th smallest number in os(0-based)

const int mod = 1000000007;
const int inf = 1e9 + 5;
const int mxN = 200005; 

int K, n, m, q;

vector<pii> g[mxN];
vector<pii> rg[mxN];

int res[mxN];

int dp[mxN][5];
void divi(int l, int r, vector<array<int,5>> upit){
    if(l > r || sz(upit) == 0)return;
    int mid = (l + r) / 2;

    ff(i,l * K, min((r + 1) * K, n) - 1){
        ff(o,0,K - 1)dp[i][o] = inf;
    }

    ff(i,mid * K,min((mid + 1) * K, n) - 1){
        ff(o,0,K - 1)dp[i][o] = inf;
        dp[i][i % K] = 0;
    }

    // desno
    ff(i,mid + 1,r){
        int L = i * K;
        int R = min((i + 1) * K, n) - 1;
        ff(j,L,R){
            for(auto c : rg[j]){
                ff(o,0,K - 1){
                    dp[j][o] = min(dp[j][o], dp[c.fi][o] + c.se);
                }
            }
        }
    }

    // levo
    fb(i,mid - 1,l){
        int L = i * K;
        int R = min((i + 1) * K, n) - 1;
        ff(j,L,R){
            for(auto c : g[j]){
                ff(o,0,K - 1){
                    dp[j][o] = min(dp[j][o], dp[c.fi][o] + c.se);
                }
            }
        }
    }

    vector<array<int,5>> todo[2];
    for(auto c : upit){
        int L = c[0];
        int R = c[1];
        int a = c[2];
        int b = c[3];
        int i = c[4];

        if(R < mid || L > mid){
            todo[L > mid].pb(c);
        }
        else{
            // mogu da odgovorim, sta vise moram
            res[i] = inf;
            ff(o,0,K - 1){
                if(dp[a][o] != inf && dp[b][o] != inf){
                    res[i] = min(res[i], dp[a][o] + dp[b][o]);
                }
            }

            if(res[i] == inf)res[i] = -1;
            
        }

    }

    divi(l, mid - 1, todo[0]); divi(mid + 1, r, todo[1]);

}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    cin >> K >> n >> m >> q; 

    map<pii,int> ima;
    ff(i,1,m){
        int u, v, w;
        cin >> u >> v >> w;
        g[u].pb({v, w});
        rg[v].pb({u, w});
        ima[{u, v}] = w;
    }

    vector<array<int,5>> upit;
    ff(i,1,q){
        int a, b;
        cin >> a >> b;

        int A = a / K, B = b / K;
        if(A == B)res[i] = -1;
        else if(B == A + 1)res[i] = (ima.count({a, b}) == 1 ? ima[{a, b}] : -1);
        else upit.pb({a / K, b / K, a, b, i});
    }

    divi(0, (n - 1) / K, upit);

    ff(i,1,q)cout << res[i] << '\n';

    return 0;
}
/*

5 14 5 5
0 5 9
5 12 10
0 7 7
7 12 8
4 7 10
0 12
0 5
0 7
7 12
0 13

// probati bojenje sahovski
*/
 
 
 
 
 

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 31 / 31
• Subtask 5: 44 / 44