Submission #415869

#	Time	Username	Problem	Language	Result	Execution time	Memory
415869		koioi.org-koosaga	Escape Route (JOI21_escape_route)	C++17	5 / 100	207 ms	130108 KiB

escape_route

#include "escape_route.h"
#include <bits/stdc++.h>
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
using namespace std;
using lint = long long;
using pi = pair<lint, lint>;
 
struct edg{
    int pos;
    lint L, C;
};
 
struct node{
    int i, j; lint max_time;
    bool operator<(const node &n)const{
        return max_time < n.max_time;
    }
};
 
lint daybreak[96][96];
lint dayfinish[96][96];
lint adj[96][96], dp[96][96];
vector<edg> gph[96];
 
vector<pi> qq[96][96];
vector<pi> prec[96][96];
lint ret[2000005];
lint S;
 
void Do(int u, int n){
	for(auto &e : gph[u]){
		int v = e.pos;
		vector<lint> dist1(n, -3e18), dist2(n, 3e18);
		// backward shortest path
		{
			dist1[u] = e.C - e.L;
			vector<int> vis(n);
			for(int it = 0; it < n; it++){
				pi ret(-5e18, 5e18);
				for(int i = 0; i < n; i++){
					if(!vis[i]) ret = max(ret, pi(dist1[i], i));
				}
				if(ret.first < 0) break;
				int x = ret.second;
				vis[x] = 1;
				for(auto &e : gph[x]){
					if(dist1[e.pos] < dist1[x] - e.L && dist1[x] < e.C){
						dist1[e.pos] = dist1[x] - e.L;
					}
				}
			}
		}
		// forward shortest path
		{
			dist2[v] = e.C;
			vector<int> vis(n);
			for(int it = 0; it < n; it++){
				pi ret(5e18, 5e18);
				for(int i = 0; i < n; i++){
					if(!vis[i]) ret = min(ret, pi(dist2[i], i));
				}
				int x = ret.second;
				if(ret.first > S) break;
				vis[x] = 1;
				for(auto &e : gph[x]){
					if(dist2[e.pos] > dist2[x] + e.L && dist2[x] + e.L <= e.C){
						dist2[e.pos] = dist2[x] + e.L;
					}
				}
			}
		}
		for(int i = 0; i < n; i++){
			for(int j = 0; j < n; j++){
				if(dist2[j] <= S && dist1[i] >= 0){
					prec[i][j].emplace_back(dist1[i], dist2[j] - dist1[i]);
				}
			}
		}
	}
	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			sort(all(prec[i][j]));
			int ptr = sz(prec[i][j]);
			lint curMin = 1e18;
			for(auto &[x, y] : qq[i][j]){
				while(ptr > 0 && prec[i][j][ptr - 1].first >= x){
					curMin = min(curMin, prec[i][j][--ptr].second);
				}
				ret[y] = min(ret[y], curMin);
			}
			prec[i][j].clear();
		}
	}
}
 
// wtf just use namespace std and pairs
std::vector<long long> calculate_necessary_time(
        int N, int M, long long Sfuck, int Q, std::vector<int> A, std::vector<int> B,
        std::vector<long long> L, std::vector<long long> C, std::vector<int> U,
        std::vector<int> V, std::vector<long long> T) {
    S = Sfuck;
    for(int i = 0; i < M; i++){
        gph[A[i]].push_back({B[i], L[i], C[i]});
        gph[B[i]].push_back({A[i], L[i], C[i]});
    }
    {
        priority_queue<node> pq;
        memset(daybreak, 0x3f, sizeof(daybreak));
        auto enq = [&](int s, int e, lint x){
            if(daybreak[s][e] > x){
                daybreak[s][e] = x;
                pq.push({s, e, -x});
            }
        };
        for(int i = 0; i < N; i++){
            enq(i, i, 0);
        }
        while(sz(pq)){
            auto x = pq.top(); pq.pop();
            x.max_time = -x.max_time;
            if(daybreak[x.i][x.j] != x.max_time) continue;
            for(auto &e : gph[x.j]){
                if(x.max_time + e.L <= e.C){
                    enq(x.i, e.pos, x.max_time + e.L);
                }
            }
        }
    }
    {
        priority_queue<node> pq;
        for(int i = 0; i < N; i++){
            for(int j = 0; j < N; j++){
                dayfinish[i][j] = -1e18;
            }
        }
        auto enq = [&](int s, int e, lint x){
            if(dayfinish[s][e] < x){
                dayfinish[s][e] = x;
                pq.push({s, e, x});
            }
        };
        for(int i = 0; i < N; i++){
            enq(i, i, S);
        }
        while(sz(pq)){
            auto x = pq.top(); pq.pop();
            if(dayfinish[x.i][x.j] != x.max_time) continue;
            for(auto &e : gph[x.i]){
                lint val = min(x.max_time, e.C) - e.L;
                if(val >= 0) enq(e.pos, x.j, val);
            }
        }
    }
    {
        memset(adj, 0x3f, sizeof(adj));
        for(int i = 0; i < N; i++){
            for(int j = 0; j < N; j++){
                if(dayfinish[i][j] >= 0) adj[i][j] = 1;
                if(i == j) adj[i][j] = 0;
            }
        }
        for(int i = 0; i < N; i++){
            for(int j = 0; j < N; j++){
                for(int k = 0; k < N; k++){
                    adj[j][k] = min(adj[j][k], adj[j][i] + adj[i][k]);
                }
            }
        }
        for(int i = 0; i < N; i++){
            for(int j = 0; j < N; j++){
                assert(adj[i][j] <= N);
                dp[i][j] = 1e18;
                for(int k = 0; k < N; k++){
                    dp[i][j] = min(adj[i][k] * S + daybreak[k][j], dp[i][j]);
                }
            }
        }
    }
    fill(ret, ret + Q, 1e18);
    for(int i = 0; i < Q; i++){
    	qq[U[i]][V[i]].emplace_back(T[i], i);
	}
    for(int i = 0; i < Q; i++){
        for(int j = 0; j < N; j++){
            if(dayfinish[U[i]][j] >= T[i]){
                ret[i] = min(ret[i], S - T[i] + dp[j][V[i]]);
            }
        }
    }
    for(int i = 0; i < N; i++){
        for(int j = 0; j < N; j++){
        	sort(all(qq[i][j]));
        	reverse(all(qq[i][j]));
        }
    }
    for(int i = 0; i < N; i++){
    	Do(i, N);
	}
    vector<lint> ans(ret, ret + Q);
    return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 35
• Subtask 5: 0 / 30