C题是不是描述有问题，还是说数据有问腿

rt，第一份代码是没有加上向上走的，只过了43.3%

#include<bits/stdc++.h>
#define int long long
#pragma GCC optimize(2)
using namespace std;
const int  N = 2e6 + 10;
int times;
int n,m;
int arr[2010][2010],vis[2010][2010];
int dx[]={0,1,-1,0};
int dy[]={1,0,0,-1}; 
void solve()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)cin>>arr[i][j],vis[i][j]=N*N;
	
	vis[1][1]=0;
	queue<pair<int,int>>Q;
	Q.push({1,1});
	while(Q.size())
	{
		auto t = Q.front();
		Q.pop();
		for(int i=0;i<3;i++)
		{
			int sx = t.first+dx[i];
			int sy = t.second+dy[i];
			if(sx>=1&&sx<=n&&sy>=1&&sy<=m)
			{
				int value = 1+(arr[t.first][t.second]!=arr[sx][sy]);
				if(value+vis[t.first][t.second]<vis[sx][sy])
				{
					vis[sx][sy] = value+vis[t.first][t.second];
					Q.push({sx,sy});
				}
			}
		}
	}
	cout<<vis[n][m]<<endl;
}

signed main()
{
	std::ios::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);
	times=1;
	//cin >> times;
	while (times--)
	{
		solve();
	}
	return 0;
}

第二份代码，加上了可以向上的方向

#include<bits/stdc++.h>
#define int long long
#pragma GCC optimize(2)
using namespace std;
const int  N = 2e6 + 10;
int times;
int n,m;
int arr[2010][2010],vis[2010][2010];
int dx[]={0,1,-1,0};
int dy[]={1,0,0,-1}; 
void solve()
{
	cin>>n>>m;
	for(int i=1;i<=n;i++)
		for(int j=1;j<=m;j++)cin>>arr[i][j],vis[i][j]=N*N;
	
	vis[1][1]=0;
	queue<pair<int,int>>Q;
	Q.push({1,1});
	while(Q.size())
	{
		auto t = Q.front();
		Q.pop();
		for(int i=0;i<4;i++)
		{
			int sx = t.first+dx[i];
			int sy = t.second+dy[i];
			if(sx>=1&&sx<=n&&sy>=1&&sy<=m)
			{
				int value = 1+(arr[t.first][t.second]!=arr[sx][sy]);
				if(value+vis[t.first][t.second]<vis[sx][sy])
				{
					vis[sx][sy] = value+vis[t.first][t.second];
					Q.push({sx,sy});
				}
			}
		}
	}
	cout<<vis[n][m]<<endl;
}

signed main()
{
	std::ios::sync_with_stdio(0);
	cin.tie(0);cout.tie(0);
	times=1;
	//cin >> times;
	while (times--)
	{
		solve();
	}
	return 0;
}