只过了一个数据，其余全部mle，求调

Relisc @ 2024-07-01 16:56:26

#include <bits/stdc++.h>
using namespace std;

typedef pair<int,int> PII;
queue <PII> q;
const int N=1050;
char a[N][N];
bool st[N][N];
int n,m;

void bfs(int u,int v){
    int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};
    st[u][v]=true;
    q.push({u,v});

    while(!q.empty())
    {
        auto t=q.front();
        q.pop();
        for(int i=0;i<4;i++)
        {
            int x=t.first+dx[i],y=t.second+dy[i];
            if(1<=x && x<=n && 1<=y && y<=m && !st[x][y] && a[x][y]=='.')
                q.push({x,y});      
        }
    }

    if(!st[n][m])   cout<<"No"<<endl;
    else    cout<<"Yes"<<endl;
}

int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            cin>>a[i][j];

    bfs(1,1);
    return 0;
}

by do_it_tomorrow @ 2024-07-01 17:00:41

#include <bits/stdc++.h>
using namespace std;

typedef pair<int,int> PII;
queue <PII> q;
const int N=1050;
char a[N][N];
bool st[N][N];
int n,m;

void bfs(int u,int v){
    int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};
    st[u][v]=true;
    q.push({u,v});

    while(!q.empty())
    {
        auto t=q.front();
        q.pop();
        for(int i=0;i<4;i++)
        {
            int x=t.first+dx[i],y=t.second+dy[i];
            if(1<=x && x<=n && 1<=y && y<=m && !st[x][y] && a[x][y]=='.')
                q.push({x,y}) ,st[x][y]=true;   //here
        }
    }

    if(!st[n][m])   cout<<"No"<<endl;
    else    cout<<"Yes"<<endl;
}

int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            cin>>a[i][j];

    bfs(1,1);
    return 0;
}

by do_it_tomorrow @ 2024-07-01 17:00:51

@Relisc

by Relisc @ 2024-07-01 17:06:10

@do_it_tomorrow 奥！忘记改状态了，谢谢~