Gourmet choice CF1131D

#include <iostream>
#include <cstring>
#include <queue>
using namespace std ;
 const int  N=4000,M =1e6+3;
 #define int long long
 int n,m, in[N],fa[N],D[N];
 int nxt[M],go[M],hd[N],all;
 void add_(int x,int y){
 	go[++all]=y,nxt[all]=hd[x]; hd[x]=all;
 }
 
 int find(int x){
 	return x==fa[x]? x:fa[x]=find(fa[x]);
 }
 void cmb(int i,int j){
 	int fx= find(i), fy=find(j);
	fa[fy]=fx; 
 }
 void Topo(){
 	int i,x,Sum=0,num=0;
 	queue<int> q;
 	for(i=1;i<=n+m;i++){
 		  int fx=find(i);if(fx!=i)continue;
		  if(in[i]==0){
		  	 q.push(i);  D[i]=1;
		  }
		  ++Sum;
	 } 
 	
 	while(q.empty()==0){
 		x=q.front(); q.pop(); num++;
 		for(i=hd[x];i;i=nxt[i]){
 			int y=go[i]; 
 			D[y]=max(D[y],D[x]+1); 
 			if(--in[y]==0) q.push(y);
		 }
	 }
	 if(Sum==num){
	 	cout<<"Yes\n";
	 	for(i=1;i<=n;i++) cout<<D[find(i)]<<' ';
	 	cout<<endl;
	 	for(i=n+1;i<=n+m;i++) cout<<D[find(i)]<<' ';
	 }
	 else{
	 	cout<<"No\n";
	 }
 }
 char op[N][N];
 
 signed main(){
 	char c; 
 	cin>>n>>m;
 	for(int i=1;i<=n+m;i++) fa[i]=i;
 	for(int i=1;i<=n;i++) 
 		for(int j=1;j<=m;j++){
 			cin>>op[i][j];  c=op[i][j];
 			
 			if(c=='=') cmb(i,n+j);
 		}
 	for(int i=1;i<=n;i++) 
 		for(int j=1;j<=m;j++){
 			if(op[i][j]=='<') 
 				in[find(j+n)]++,add_(find(i),find(j+n));
 			if(op[i][j]=='>')
 				in[find(i)]++,add_(find(j+n),find(i));
 		}	
 	Topo() ;
 }