#include <bits/stdc++.h> // By Lucky Ox
using namespace std;
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define int long long
#define endl '\n'
#define pii pair<int, int>

const int N = 3e2 + 10;
int n, m;
char g[N][N];
bool vs[N][N];
map<char, pii[2]> mp;
int dx[] = {0, 1, 0, -1, 0}, dy[] = {0, 0, 1, 0, -1};

int bfs(int fx, int fy){
    queue<pair<pii, int> >q;
    q.push({{fx, fy}, 0});
    vs[fx][fy] = 1;

    while(q.size()){
        auto now = q.front();
        q.pop();

        int x = now.first.first, y = now.first.second, cnt = now.second;

        if(g[x][y] == '=') return cnt;

        for(int i = 1; i <= 4; i ++ ){
            int nx = x + dx[i], ny = y + dy[i];
            if(g[nx][ny] != '#' && !vs[nx][ny]){
                vs[nx][ny] = 1;
                if(g[nx][ny] >= 'A' && g[nx][ny] <= 'Z'){
                    char op = g[nx][ny];
                    
                    if(mp[op][0].first == nx && mp[op][0].second == ny)
                        nx = mp[op][1].first, ny = mp[op][1].second;
                    else 
                        nx = mp[op][0].first, ny = mp[op][0].second;
                }

                q.push({{nx, ny}, cnt + 1});
            }
        }
    }
}
signed main(){
    IOS;
    cin >> n >> m;

    int fx = 0, fy = 0;
    for(int i = 1; i <= n; i ++ )
        for(int j = 1; j <= m; j ++ ){
            cin >> g[i][j];
            
            if(g[i][j] == '@') fx = i, fy = j;
            else if(g[i][j] >= 'A' && g[i][j] <= 'Z'){
                if (mp[g[i][j]][0].first == 0)
                    mp[g[i][j]][0].first = i, mp[g[i][j]][0].second = j;
                else 
                    mp[g[i][j]][1].first = i, mp[g[i][j]][1].second = j;
            }
        }

    cout << bfs(fx, fy);
    return 0;
}

代码如上 我感觉是map那里出问题了 但我看不出来 太弱了 orz orz