Submission #1096663

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096663		azberjibiou	Sky Walking (IOI19_walk)	C++17	100 / 100	1190 ms	135828 KiB

walk

#include "walk.h"
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define pb push_back
#define lb lower_bound
#define gibon ios::sync_with_stdio(false); cin.tie(0);
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
typedef long long ll;
using namespace std;
const int mxN=100050;
const int mxM=10000;
const int mxK=60;
const ll INF=1e18;
struct line{
    int l, r, h;
};
int N, M;
int pos[mxN], A[mxN];
line B[mxN];
int st, en;
int sidx, eidx;
map <pii, int> vtx;
pii V[12*mxN];
int vidx;
vector <pll> adj[12*mxN];
/*
void input(){
    cin >> N >> M;
    for(int i=0;i<N;i++) cin >> pos[i];
    for(int i=0;i<N;i++) cin >> A[i];
    for(int i=1;i<=M;i++) cin >> B[i].l >> B[i].r >> B[i].h;
    for(int i=1;i<=M;i++) B[i].l=pos[B[i].l], B[i].r=pos[B[i].r];
    cin >> st >> en;
}
*/
void no_endpoint(){
    vector <line> v;
    for(int i=1;i<=M;i++) v.push_back(B[i]);
    sort(all(v), [](line a, line b){return a.h!=b.h ? a.h<b.h : a.l<b.l;});
    vector <line> res;
    line prev={-1, -1, -1};
    for(line x : v){
        if(x.h!=prev.h || prev.r<x.l){
            if(prev.h!=-1) res.push_back(prev);
            prev=x;
        }
        else prev.r=x.r;
    }
    if(prev.h!=-1) res.push_back(prev);
    M=res.size();
    for(int i=1;i<=M;i++) B[i]=res[i-1];
}
void init(vector <int> x, vector <int> h, vector <int> l, vector <int> r, vector <int> y, int s, int g){
    N=x.size(); M=l.size();
    for(int i=0;i<N;i++) pos[i]=x[i];
    for(int i=0;i<N;i++) A[i]=h[i];
    for(int i=1;i<=M;i++) B[i].l=l[i-1], B[i].r=r[i-1], B[i].h=y[i-1];
  	for(int i=1;i<=M;i++) B[i].l=pos[B[i].l], B[i].r=pos[B[i].r];
    no_endpoint();
    st=s, en=g;
}
void add_edge(int a, int b, int c){
    adj[a].emplace_back(b, c);
    adj[b].emplace_back(a, c);
}
void add(vector <int> &v1, int val, pii rng){
    if(val==-1) return;
    if(val>rng.se || val<rng.fi) return;
    v1.push_back(val);
}
int lb(set <int> &s, int val){
    auto it=s.lower_bound(val);
    return (it==s.end() ? -1 : *it);
}
int rb(set <int> &s, int val){
    auto it=s.lower_bound(val+1);
    if(it==s.begin()) return -1;
    it--;
    return *it;
}
void make_graph(){
    set <int> xcr;
    set <pii> fall; // x값, 끝점 index
    vector <pii> hv;
    for(int i=0;i<N;i++) hv.emplace_back(A[i], i);
    sort(all(hv));
    vector <int> turn;
    for(int i=1;i<=M;i++) turn.push_back(i);
    sort(all(turn), [&](int a, int b){return B[a].h>B[b].h;});
    for(int now : turn){
        auto [nl, nr, nh]=B[now];
        while(hv.size() && hv.back().fi>=nh){
            int idx=hv.back().se;
            hv.pop_back();
            xcr.insert(pos[idx]);
        }
        vector <int> cr;
        vector <pii> up; // x값, 끝점 index
        vector <int> down;
        //get up edges
        while(true){
            if(fall.empty()) break;
            auto it=fall.lower_bound(pii(nl, 0));
            if(it==fall.end() || it->fi>nr) break;
            up.push_back(*it);
            fall.erase(it);
        }
        // add down vertices
        add(down, lb(xcr, nl), pii(nl, nr));
        if(nl<=pos[st] && pos[st]<=nr){
            add(down, lb(xcr, pos[st]), pii(nl, nr));
            add(down, rb(xcr, pos[st]), pii(nl, nr));
        }
        if(nl<=pos[en] && pos[en]<=nr){
            add(down, lb(xcr, pos[en]), pii(nl, nr));
            add(down, rb(xcr, pos[en]), pii(nl, nr));
        }
        add(down, rb(xcr, nr), pii(nl, nr));
        sort(all(down));
        down.erase(unique(all(down)), down.end());
        /*
        printf("nl, nr, nh=%d %d %d\n", nl, nr, nh);
        for(int x : down) printf("%d ", x);
        printf("\n");
        printf("xcr: ");
        for(int x : xcr) printf("%d ", x);
        printf("\n");
        */
        //make vertices
        for(int x : down) cr.push_back(x);
        for(auto [x, idx] : up) cr.push_back(x);
        sort(all(cr));
        cr.erase(unique(all(cr)), cr.end());
        for(int i=0;i<cr.size();i++){
            int x=cr[i];
            if(vtx.count(pii(x, nh))==0){
              	V[vidx]=pii(x, nh);
            	vtx[pii(x, nh)]=vidx++;
            }
            //also make horizontal edges
            if(i-1>=0) add_edge(vtx[pii(x, nh)], vtx[pii(cr[i-1], nh)], cr[i]-cr[i-1]);
        }
        //make up edges
        for(auto [x, num1] : up){
            int num2=vtx[pii(x, nh)];
            add_edge(num1, num2, V[num1].se-nh);
        }
        //make down edges
        for(int x : down){
            fall.insert(pii(x, vtx[pii(x, nh)]));
        }
    }
    //make st and en
    V[vidx]=pii(pos[st], 0);
    vtx[pii(pos[st], 0)]=vidx;
    sidx=vidx++;
    V[vidx]=pii(pos[en], 0);
    vtx[pii(pos[en], 0)]=vidx;
    eidx=vidx++;
    //adding edge for st and en
    auto itst=fall.lower_bound(pii(pos[st], 0));
    if(itst!=fall.end() && itst->fi==pos[st]){
        int nxt=itst->se;
        add_edge(sidx, nxt, V[nxt].se);
    }
    auto iten=fall.lower_bound(pii(pos[en], 0));
    if(iten!=fall.end() && iten->fi==pos[en]){
        int nxt=iten->se;
        add_edge(eidx, nxt, V[nxt].se);
    }
    /*
    for(int i=0;i<vidx;i++) printf("V[%d]=%d %d\n", i, V[i].fi, V[i].se);
    for(int i=0;i<vidx;i++){
        printf("i=%d: ", i);
        for(auto [x, y] : adj[i]) printf("(%lld %lld) ", x, y);
        printf("\n");
    }
    */
}
ll dist[12*mxN];
ll ans;
void dijkstra(){
    for(int i=0;i<vidx;i++) dist[i]=-1;
    priority_queue <pll> pq;
    pq.emplace(0, sidx);
    while(pq.size()){
        auto [x, now]=pq.top();
        pq.pop();
        if(dist[now]!=-1) continue;
        dist[now]=-x;
        for(auto [nxt, val] : adj[now]) pq.emplace(x-val, nxt);
    }
    //for(int i=0;i<vidx;i++) printf("dist[%d]=%lld\n", i, dist[i]);
    ans=dist[eidx];
}
long long min_distance(std::vector<int> x, std::vector<int> h, std::vector<int> l, std::vector<int> r, std::vector<int> y, int s, int g) {
	init(x, h, l, r, y, s, g);
    make_graph();
    dijkstra();
    return ans;
}
/*
int main(){
    gibon
    input();
    make_graph();
    dijkstra();
    cout << ans;
}
*/
/*
7 7
0 3 5 7 10 12 14
8 7 9 7 6 6 9
0 1 1
0 2 6
0 6 8
2 3 1
2 6 7
3 4 2
4 6 5
1 5
*/

Compilation message (stderr)

walk.cpp: In function 'void make_graph()':
walk.cpp:139:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |         for(int i=0;i<cr.size();i++){
      |                     ~^~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 18 / 18
• Subtask 5: 43 / 43