优先队列  bfs

#include 
     
      using namespace std;typedef long long ll ;typedef double    dl ;#define INF 0x7fconst int  inf = 987654321;const int sz = 505 ;const int mod = 1e9 + 7;const int sqrtn = 300;#define f(i,l,r) for(int i=l;i<=r;++i)#define g(i,l,r) for(int i=l;i>=r;--i)#define CLR(arr,val) memset(arr,val,sizeof(arr))#define FAST_IO ios::sync_with_stdio(false);cin.tie(0);#define pii pair
      
       #define lowbit(x) x&(-x)#define X first#define Y second ll g[sz][sz]; int T,n,m;struct node{    int x, y;    ll cost;    node(int _x,int _y,ll _c):x(_x),y(_y),cost(_c){}    node(){}    bool operator<(const node&b)const    {        return cost > b.cost;    }}; bool vis[sz][sz]; int dir[4][2] = { -1,0,1,0,0,-1,0,1 }; ll bfs(){    priority_queue 
       
         q ;     CLR(vis,0);      f(i,1,m-1)      if(g[1][i]!=-1)         q.push(node(1,i,g[1][i]));     f(i,1,n)         if(g[i][m]!=-1)             q.push(node(i,m,g[i][m]));     while(!q.empty())    {         node x = q.top();q.pop();         if(vis[x.x][x.y])continue;         vis[x.x][x.y] =1;         if(x.x==n || x.y ==1) return x.cost;         f(i,0,3)         {             int dx = x.x +dir[i][0];             int dy = x.y+ dir[i][1];             if(dx<1||dx>n||dy<1||dy>m) continue;             if(g[dx][dy]==-1)continue;             if(vis[dx][dy])continue;             q.push(node(dx,dy,x.cost+g[dx][dy]));         }    }    return -1;     }void work(){    cin>>T>>n>>m;    while(T--)    {        f(i,1,n)f(j,1,m)cin>>g[i][j];        f(i,1,n)f(j,1,m)         if(g[i][j] ==-1)   g[i][j]=0;        else if( g[i][j] ==0)   g[i][j]=-1;         cout<
        
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