关于时间复杂度

#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include<ext/pb_ds/hash_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("Ofast")
typedef long long ll;
typedef pair<int,int> pii;
#define mk(a,b) make_pair((a),(b))
#define int ll

const int maxn=2010;
const int inf=1e12;
const int mod=1e9+7;
int n,m,k,ans1=1,ans2=1;
int a[maxn][maxn];
int nx[maxn][maxn],ny[maxn][maxn],mp[maxn][maxn],p[maxn][maxn];

inline int read() {
	int s=0,w=1;
	char ch=getchar();
	while(!isdigit(ch)) {
		if(ch=='-') w=-1;
		ch=getchar();
	}
	while(isdigit(ch)) s=s*10+ch-'0',ch=getchar();
	return s*w;
}

inline void write(int x) {
	if(x<0) x=-x,putchar('-');
	if(x>9) write(x/10);
	putchar('0'+x%10);
}

signed main() {
	n=read(),m=read();
	memset(a,-1,sizeof a);
	for(int i=1; i<=n; ++i)
		for(int j=1; j<=m; ++j) {
			a[i][j]=read();
		}
	for(int i=1; i<=n; ++i) {
		nx[i][m]=m;
		for(int j=m-1; j>=1; --j) {
			if(a[i][j]!=a[i][j+1]) nx[i][j]=nx[i][j+1];
			else nx[i][j]=j;
		}
	}
	for(int i=1; i<=m; ++i) {
		ny[n][i]=n;
		for(int j=n-1; j>=1; --j) {
			if(a[j][i]!=a[j+1][i]) ny[j][i]=ny[j+1][i];
			else ny[j][i]=j;
		}
	}
	for(int i=1; i<=n; ++i)
		for(int j=1; j<=m; ++j) {
			int mx=inf;
			for(int k=i; k<=ny[i][j]; ++k) {
				mx=min(mx,nx[k][j]);
				mp[i][j]=max(mp[i][j],(mx-j+1)*(k-i+1));
				p[i][j]=max(p[i][j],min(mx-j+1,k-i+1)*min(mx-j+1,k-i+1));
			}
		}
	for(int i=1; i<=n; ++i)
		for(int j=1; j<=m; ++j) {
			ans1=max(ans1,p[i][j]);
			ans2=max(ans2,mp[i][j]);
		}
	write(ans1),puts(""),write(ans2);
	return 0;
}

/*
3 3
1 0 1
0 0 1
1 1 0
*/