0 分，不过样例，玄关求助

QAQ_liu @ 2024-08-21 16:23:10

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m,sum,d[4][2]={{0,1},{1,0},{0,-1},{-1,0}};
char a[1005][1005];
void dfs(int x,int y,int s){
    int nx,ny;
    char h;
    if(x==n&&y==m) sum=max(sum,s);
    if(a[x][y]=='1') h='1';
    else h='0';
    for(int i=0;i<4;i++){
        nx=x+d[i][0];
        ny=y+d[i][1];
        if(nx<1||ny<1||nx>n||ny>n) continue;
        if(a[nx][ny]=='1'&&h!=a[nx][ny]) dfs(nx,ny,s+1);
        else continue;
    }
}
signed main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++) cin>>a[i][j];
    }
    while(m--){
        sum=0;
        int x,y;
        cin>>x>>y;
        dfs(x,y,0);
        cout<<sum<<"\n";
    }
    return 0;
}

by xionghao2013 @ 2024-08-21 16:56:02

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m,sum,d[4][2]={{0,1},{1,0},{0,-1},{-1,0}};
char a[1005][1005];
bool vis[1005][1005];
void dfs(int x,int y,int s){
    if (vis[x][y]) return;
    vis[x][y]=1;
    int nx,ny;
    char h;
    sum=max(sum,s);
    if(a[x][y]=='1') h='1';
    else h='0';
    for(int i=0;i<4;i++){
        nx=x+d[i][0];
        ny=y+d[i][1];
        if(nx<1||ny<1||nx>n||ny>n) continue;
        if(h!=a[nx][ny]) dfs(nx,ny,s+1);
        else continue;
    }
}
signed main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++) cin>>a[i][j];
    }
    while(m--){
        memset(vis,0,sizeof(vis));
        sum=0;
        int x,y;
        cin>>x>>y;
        dfs(x,y,1);
        cout<<sum<<"\n";
    }
    return 0;
}

改好之后的代码

by xionghao2013 @ 2024-08-21 16:58:03

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m,sum,d[4][2]={{0,1},{1,0},{0,-1},{-1,0}};
char a[1005][1005];
bool vis[1005][1005];
void dfs(int x,int y,int s){
    if (vis[x][y]) return;
    vis[x][y]=1;
    int nx,ny;
    char h;
    sum=max(sum,s);
    if(a[x][y]=='1') h='1';
    else h='0';
    for(int i=0;i<4;i++){
        nx=x+d[i][0];
        ny=y+d[i][1];
        if(nx<1||ny<1||nx>n||ny>n) continue;
        if(h!=a[nx][ny]) dfs(nx,ny,s+1);
        else continue;
    }
}
signed main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++) cin>>a[i][j];
    }
    while(m--){
        memset(vis,0,sizeof(vis));
        sum=0;
        int x,y;
        cin>>x>>y;
        dfs(x,y,1);
        cout<<sum<<"\n";
    }
    return 0;
}

by xionghao2013 @ 2024-08-21 17:00:45

#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,m,sum,d[4][2]={{0,1},{1,0},{0,-1},{-1,0}};
char a[1005][1005];
bool vis[1005][1005];
void dfs(int x,int y,int s){
    if (vis[x][y]) return;
    vis[x][y]=1;
    int nx,ny;
    char h;
    sum=max(sum,s);
    if(a[x][y]=='1') h='1';
    else h='0';
    for(int i=0;i<4;i++){
        nx=x+d[i][0];
        ny=y+d[i][1];
        if(nx<1||ny<1||nx>n||ny>n) continue;
        if(h!=a[nx][ny]) dfs(nx,ny,s+1);
        else continue;
    }
}
signed main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++) cin>>a[i][j];
    }
    while(m--){
        memset(vis,0,sizeof(vis));
        sum=0;
        int x,y;
        cin>>x>>y;
        dfs(x,y,1);
        cout<<sum<<"\n";
    }
    return 0;
}

by xionghao2013 @ 2024-08-21 17:02:05

后面不要at我了，我后面有事（一直到7：30）

by QAQ_liu @ 2024-10-02 20:41:46

@xionghao2013 也是错的0分

by xionghao2013 @ 2024-10-03 10:45:27

https://www.luogu.com.cn/record/179609484

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int a[1005][1005],vis[1005][1005],ans[1005][1005],s[1000005];
int dx[10]={0,-1,0,1,0};
int dy[10]={0,0,-1,0,1};
int n;
void dfs(int nx,int ny,int col)
{
    ans[nx][ny]=col;
    s[col]++;
    vis[nx][ny]=true;
    for (int i=1;i<=4;i++)
    {
        int tx,ty;
        tx=nx+dx[i];
        ty=ny+dy[i];
        if (tx<=n&&ty<=n&&tx>=1&&ty>=1&&!vis[tx][ty]&&a[tx][ty]!=a[nx][ny])
        {
            dfs(tx,ty,col);
        }
    }
}
int main(){
    int m;
    cin>>n>>m;
    for (int i=1;i<=n;i++)
    {
        for (int j=1;j<=n;j++)
        {
            char c;
            cin>>c;
            a[i][j]=c-'0';
        }
    }
    int cur=0;
    for (int i=1;i<=n;i++)
    {
        for (int j=1;j<=n;j++)
        {
            if (!vis[i][j])
            {
                dfs(i,j,++cur);
            }
        }
    }
    for (int i=1;i<=m;i++)
    {
        int x,y;
        cin>>x>>y;
        cout<<s[ans[x][y]]<<endl;
    }
    return 0;
}