| 比赛 |
NOIP2025模拟赛4 |
评测结果 |
AAAAAAAAAAAAAAAAAAAA |
| 题目名称 |
Daily Commute |
最终得分 |
100 |
| 用户昵称 |
淮淮清子 |
运行时间 |
1.101 s |
| 代码语言 |
C++ |
内存使用 |
12.36 MiB |
| 提交时间 |
2025-11-27 11:29:59 |
显示代码纯文本
#include<iostream>
#include<queue>
#include<cstring>
#include<ctime>
#include<algorithm>
using namespace std;
#define int long long
const int MAXN = 200005;
const int MAXM = MAXN << 1;
const int INF = 0x3f3f3f3f3f3f3f3f;
int n, w, d, tot = 0;
struct node{
int to, nxt, len;
}e[MAXM << 1];
int h[MAXN];
int dis[MAXN], a[MAXN], pos[MAXN];
bool vis[MAXN];
struct Node{
int pos, id, dis;
bool operator<(const Node &x)const{
return x.dis < dis;
}
};
priority_queue<Node> q;
void add(int x, int y, int len){
e[++ tot] = {y, h[x], len};
h[x] = tot;
}
signed main(){
freopen("Commute.in", "r", stdin);
freopen("Commute.out", "w", stdout);
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n >> w >> d;
for(int i = 1;i <= w;i ++){
int u, v; cin >> u >> v;
add(v, u, 1);
}
memset(dis, 0x3f, sizeof(dis));
queue<int> Q;
dis[n] = 0; vis[n] = 1; Q.push(n);
while(!Q.empty()){
int u = Q.front(); Q.pop();
for(int i = h[u];i;i = e[i].nxt){
int v = e[i].to;
if(!vis[v]){
dis[v] = dis[u] + 1;
vis[v] = 1;
Q.push(v);
}
}
}
for(int i = 1;i <= n;i ++){
cin >> a[i]; pos[a[i]] = i;
q.push({i, a[i], i + dis[a[i]] - 1});
}
int now = dis[1];
/*
T(i) = (i − 1) + d(S_i) = i + d(S_i) − 1
T(i), d(1), pos(n) - 1
*/
while(d --){
int x, y; cin >> x >> y;
swap(pos[a[x]], pos[a[y]]);
q.push({x, a[y], x + dis[a[y]] - 1});
q.push({y, a[x], y + dis[a[x]] - 1});
swap(a[x], a[y]);
while(!q.empty() && pos[q.top().id] != q.top().pos) q.pop();
cout << min({q.top().dis, now, pos[n] - 1}) << '\n';
}
// cerr << "Time : " << clock() / CLOCKS_PER_SEC << "s \n";
return 0;
}