根号分治做法WA求调

#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=405,sqrn=405;
const ll mod=998244353;
int n;
ll dp[sqrn][N][N];
ll a[N][N];
ll tj[N*N];
ll tag[N],len;
vector<int> gx[N*N],gy[N*N];
ll pf[N][N];
int main(){
	cin >>n;
	for(int i=0;i<=n;i++)
	 	for(int j=0;j<=n;j++)
	 		for(int k=1;k<=400;k++)dp[k][i][j]=0;
	for(int i=1;i<=n;i++){
	 	for(int j=1;j<=n;j++){
	 		
	 		cin>>a[i][j];
	 		gx[a[i][j]].push_back(i);
	 		gy[a[i][j]].push_back(j);
	 		tj[a[i][j]]++;
	 		if(i==1 && j==1)pf[i][j]=1;
	 		else pf[i][j]=(pf[i-1][j]+pf[i][j-1])%mod;
		}
	}
	
	for(int i=1;i<=n*n;i++){
		if(tj[i]>400)tag[i]=++len;
	}
		
	ll ans=0;
	for(int i=1;i<=n;i++){
	 	for(int j=1;j<=n;j++){
	 		if(!tag[a[i][j]]){
	 			for(int k=0;k<gx[a[i][j]].size();k++){
	 				int dx=i-gx[a[i][j]][k],dy=j-gy[a[i][j]][k];
	 				if(dx>=0 &&dy>=0){
	 					ans=(ans+pf[dx+1][dy+1])%mod;
					 }
				}
			}else{
				dp[tag[a[i][j]]][i][j]=1;
				dp[tag[a[i][j]]][i][j]+=dp[tag[a[i][j]]][i-1][j];
				dp[tag[a[i][j]]][i][j]+=dp[tag[a[i][j]]][i][j-1];
				dp[tag[a[i][j]]][i][j]%=mod;
				ans=(ans+dp[tag[a[i][j]]][i][j])%mod;
			}
	 		
		}
	}
	cout<<ans;
	return 0;
}