2018年湘潭大学程序设计竞赛 F - maze

把点抽出来 跑个最短路就好啦。

 #include<bits/stdc++.h>
 #define LL long long
 #define pii pair<int,int>
 #define mk make_pair
 #define fi first
 #define se second
 using namespace std;

 const int N=+;
 const int M=1e5+;
 const int inf=0x3f3f3f3f;
 const LL INF=0x3f3f3f3f3f3f3f3f;
 const int mod=1e9+;

 int n, m, q, idx, S, T, d[N * N], hs[N][N], dx[] = {, -, , }, dy[] = {, , , -};
 char s[N][N];

 vector<pii> edge[N * N];

 int Dj(int S, int T) {
     priority_queue<pii, vector<pii>, greater<pii> > que;
     d[S] = ; que.push(mk(, S));
     while(!que.empty()) {
         pii u = que.top();
         que.pop();
         if(u.fi < d[u.se]) continue;
         if(u.se == T) {
             return u.fi;
         }
         for(pii v : edge[u.se]) {
             if(d[u.se] + v.fi < d[v.se]) {
                 d[v.se] = d[u.se] + v.fi;
                 que.push(mk(d[v.se], v.se));
             }
         }
     }
     return -;
 }
 void init() {
     idx = ;
     for(int i = ; i <= n * n + ; i++)
         edge[i].clear(), d[i] = inf;
 }

 bool check(int x, int y) {
     if(x > n || x < ) return false;
     if(y > m || y < ) return false;
     if(s[x][y] == '#') return false;
     return true;
 }
 int main() {
     while(scanf("%d%d%d", &n, &m, &q) != EOF) {
         init();
         for(int i = ; i <= n; i++)
             scanf("%s", s[i] + );
         for(int i = ; i <= n; i++) {
             for(int j = ; j <= m; j++) {
                 hs[i][j] = ++idx;
                 if(s[i][j] == 'S') S = idx;
                 if(s[i][j] == 'T') T = idx;
             }
         }

         for(int i = ; i <= n; i++) {
             for(int j = ; j <= m; j++) {
                 if(s[i][j] == '#') continue;
                 for(int k = ; k < ; k++) {
                     int nx_x = i + dx[k];
                     int nx_y = j + dy[k];
                     if(check(nx_x, nx_y)) {
                         edge[hs[i][j]].push_back(mk(, hs[nx_x][nx_y]));
                     }
                 }
             }
         }

         for(int i = ; i <= q; i++) {
             int a, b, c, d;
             scanf("%d%d%d%d", &a, &b, &c, &d);
             a++, b++, c++, d++;
             if(s[a][b] == '#' || s[c][d] == '#') continue;
             edge[hs[a][b]].push_back(mk(, hs[c][d]));
         }

         int ans = Dj(S, T);
         printf("%d\n", ans);
     }
     return ;
 }
 /*
 */