結果
| 問題 |
No.1323 うしらずSwap
|
| ユーザー |
 milanis48663220
|
| 提出日時 | 2020-12-20 15:27:34 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 1,465 ms / 3,000 ms |
| コード長 | 5,946 bytes |
| コンパイル時間 | 1,373 ms |
| コンパイル使用メモリ | 105,140 KB |
| 最終ジャッジ日時 | 2025-01-17 04:52:19 |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 59 |
ソースコード
#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cassert>
#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
using namespace std;
typedef long long ll;
const int INF = 1e+9;
typedef pair<int, int> P;
struct edge{
int to;
int cost;
};
void dijkstra(int s, int num_v, vector<edge> G[], int d[]){
priority_queue<P, vector<P>, greater<P>> que;
fill(d, d+num_v, INF);
d[s] = 0;
que.push(P(0, s));
while(!que.empty()){
P p = que.top();que.pop();
int v = p.second;
if(d[v] < p.first) continue;
for(int i = 0; i < G[v].size(); i++){
edge e = G[v][i];
if(d[v] + e.cost < d[e.to]){
d[e.to] = d[v] + e.cost;
que.push(P(d[e.to], e.to));
}
}
}
}
int h, w, ra, ca, rb, cb;
char s[1500][1500];
int dh[4] = {0, 0, -1, 1};
int dw[4] = {-1, 1, 0, 0};
bool is_in_field(int i, int j){
return i >= 0 && i < h && j >= 0 && j < w;
}
int to_idx(int i, int j){
return i*w+j;
}
int to_i(int idx){
return idx/w;
}
int to_j(int idx){
return idx%w;
}
void input(){
cin >> h >> w >> ra >> ca >> rb >> cb;
ra--; ca--; rb--; cb--;
for(int i = 0; i < h; i++){
for(int j = 0; j < w; j++){
cin >> s[i][j];
}
}
}
vector<edge> G[1333*1333];
int dist[1333*1333];
vector<P> get_shortest_path(){
int cur_h = rb, cur_w = cb;
vector<P> ans;
ans.push_back(P(cur_h, cur_w));
while(cur_h != ra || cur_w != ca){
for(int i = 0; i < 4; i++){
int h_to = cur_h+dh[i];
int w_to = cur_w+dw[i];
if(is_in_field(h_to, w_to) && dist[to_idx(h_to, w_to)] == dist[to_idx(cur_h, cur_w)]-1){
cur_h = h_to;
cur_w = w_to;
break;
}
}
ans.push_back(P(cur_h, cur_w));
}
return ans;
}
vector<edge> G_rem[1333*1333];
bool used_in_path[1333][1333];
void make_g_rem(){
for(int i = 0; i < h; i++){
for(int j = 0; j < w; j++){
if(s[i][j] == '#') continue;
for(int k = 0; k < 4; k++){
int i_to = i+dh[k], j_to = j+dw[k];
if(is_in_field(i_to, j_to) && s[i_to][j_to] == '.'){
if(used_in_path[i][j] && used_in_path[i_to][j_to]) continue;
G_rem[to_idx(i, j)].push_back((edge){to_idx(i_to, j_to), 1});
}
}
}
}
}
// 三箇所と繋がっているところまでの距離
int calc_dist_three(int from){
vector<int> dist(h*w, INF);
queue<int> que;
dist[from] = 0;
que.push(from);
while(!que.empty()){
int v = que.front(); que.pop();
int cnt = 0;
int i = to_i(v), j = to_j(v);
assert(s[i][j] == '.');
for(int k = 0; k < 4; k++){
int i_to = i+dh[k], j_to = j+dw[k];
if(is_in_field(i_to, j_to) && s[i_to][j_to] == '.'){
cnt++;
if(dist[to_idx(i_to, j_to)] == INF){
dist[to_idx(i_to, j_to)] = dist[v]+1;
que.push(to_idx(i_to, j_to));
}
}
}
if(cnt >= 3){
return dist[v];
}
}
return INF;
}
int dist_rem[1333*1333];
void solve(){
for(int i = 0; i < h; i++){
for(int j = 0; j < w; j++){
if(s[i][j] == '#') continue;
for(int k = 0; k < 4; k++){
int i_to = i+dh[k], j_to = j+dw[k];
if(is_in_field(i_to, j_to) && s[i_to][j_to] == '.'){
G[to_idx(i, j)].push_back((edge){to_idx(i_to, j_to), 1});
}
}
}
}
dijkstra(to_idx(ra, ca), h*w, G, dist);
if(dist[to_idx(rb, cb)] == INF){
cout << -1 << endl;
return;
}
vector<P> path = get_shortest_path();
for(auto p : path){
used_in_path[p.first][p.second] = true;
// cout << p.first << ',' << p.second << endl;
}
make_g_rem();
// dijkstraっぽい感じ
int min_diff = INF;
priority_queue<P, vector<P>, greater<P>> que;
fill(dist_rem, dist_rem+h*w, INF);
for(auto p : path){
int idx = to_idx(p.first, p.second);
dist_rem[idx] = dist[idx];
if(p.first == rb && p.second == cb) continue;
que.push(P(dist[idx], idx));
}
while(!que.empty()){
P p = que.top();que.pop();
int v = p.second;
if(dist_rem[v] < p.first) continue;
for(int i = 0; i < G_rem[v].size(); i++){
edge e = G_rem[v][i];
if(dist_rem[v] + e.cost < dist_rem[e.to] && e.to != to_idx(rb, cb)){
dist_rem[e.to] = dist_rem[v] + e.cost;
que.push(P(dist_rem[e.to], e.to));
}
if(used_in_path[to_i(e.to)][to_j(e.to)] && e.to != to_idx(ra, ca)){
chmin(min_diff, dist_rem[v] + e.cost - dist_rem[e.to]);
// cout << to_i(v) << ',' << to_j(v) << ' ' << to_i(e.to) << ',' << to_j(e.to) << endl;
}
}
}
assert(min_diff >= 0);
int tmp = calc_dist_three(to_idx(ra, ca));
if(tmp != INF) chmin(min_diff, 4*(tmp+1));
tmp = calc_dist_three(to_idx(rb, cb));
if(tmp != INF) chmin(min_diff, 4*(tmp+1));
if(min_diff == INF){
cout << -1 << endl;
}else{
cout << 2*dist[to_idx(rb, cb)]+min_diff << endl;
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cout << setprecision(10) << fixed;
input();
solve();
}