Submission #948336

#	Time	Username	Problem	Language	Result	Execution time	Memory
948336		steveonalex	Toll (BOI17_toll)	C++14	100 / 100	91 ms	16724 KiB

toll

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, char separator = ' ', char finish = '\n'){
        for(auto item: container) cout << item << separator;
        cout << finish;
    }
 template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }
 
const long N = 5e4 + 69, INF = 1e9 + 69;
long k, n, m, o;
vector<pair<long, long>> graph[N], rgraph[N];
long ans[N];
pair<long, long> queries[N];
long dp[N];
 
void dfs(long l, long r, vector<long> cur){
    if (l >= r) return;
    long mid = (l + r) >> 1;
    vector<long> L, R, pending;
    for(long i: cur){
        if (queries[i].second / k < mid) L.push_back(i);
        else if (queries[i].first / k > mid) R.push_back(i);
        else pending.push_back(i);
    }
 
    if (L.size()) dfs(l, mid - 1, L);
    if (R.size()) dfs(mid + 1, r, R);
    if (pending.empty()) return;
 
    for(long i = mid * k; i < (mid + 1) * k; ++i) {
        for(long j = mid * k; j < (mid + 1) * k; ++j) dp[j] = INF;
        dp[i] = 0;
        for(long i = mid * k - 1; i >= l * k; --i) {
            dp[i] = INF;
            for(auto j: graph[i]) minimize(dp[i], dp[j.first] + j.second);
        }
        for(long i = (mid+1) * k; i < (r+1) * k; ++i) {
            dp[i] = INF;
            for(auto j: rgraph[i]) minimize(dp[i], dp[j.first] + j.second);
        }  
        for(long i: pending){
            minimize(ans[i], dp[queries[i].first] + dp[queries[i].second]);
        }
    }
}
 
int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
 
    cin >> k >> n >> m >> o;
    while(m--){
        long u, v, w; cin >> u >> v >> w;
        graph[u].push_back({v, w});
        rgraph[v].push_back({u, w});
    }
 
    vector<long> cur(o);
    for(long i = 0; i<o; ++i) {
        cin >> queries[i].first >> queries[i].second;
        cur[i] = i;
        ans[i] = INF;
    }
    dfs(0, (n + k - 1) / k, cur);
 
    for(long i = 0; i<o; ++i) if (ans[i] == INF) cout << -1 << "\n";
        else cout << ans[i] << "\n";
 
    return 0;
}

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