#include <bits/stdc++.h>
#include "city.h"
using namespace std;
#define mp make_pair
#define fi first
#define se second
#define all(v) v.begin(),v.end()
#define allarr(a) a , a + n
#define ll long long
#define ull unsigned long long
#define pb push_back
#define fastio ios_base::sync_with_stdio(false) ; cin.tie(NULL); cout.tie(NULL)
typedef pair<int, int> pi;
typedef pair<ll,ll> pll;
typedef pair<int,pi> trp ;
typedef vector<pi> vpi;
typedef vector<pll> vpll ;
// int ab (int x ) { return (x>0?x:-x); }
ll ans ;
int root ;
const int N = 2e3+5;
int visited[N] ;
const ll mod = 1e9 ;
int notE[N][N],x[N],y[N];
void bfs(int root ){
int u = root;
queue<int> q;
q.push(u);
visited[u]=0;
int dx [][2] ={{0,-1},{0,1},{1,0},{-1,0}};
while(!q.empty()){
u = q.front();
q.pop();
// cout << visited[u]<<" " << ans <<endl;
if( u >= root )ans += visited[u] , ans %= mod;
for(int i = 0 ; i < 4 ; i++ ){
int xx = x[u]+dx[i][0] ;
int yy = y[u]+dx[i][1] ;
if( xx >= 0 && yy >= 0 &¬E[xx][yy]!=-1&& visited[notE[xx][yy]]==-1 ){
visited[notE[xx][yy]] = visited[u]+1;
q.push(notE[xx][yy]);
}
}
}
}
int DistanceSum(int N, int *X, int *Y){
memset(notE,-1,sizeof notE);
for(int i = 0 ; i < N ; i++ ){
notE[X[i]][Y[i]]=i;
x[i] = X[i] ;
y[i] = Y[i] ;
}
for(int i = 0 ; i < N ; i++ ){
memset(visited,-1,sizeof visited) ;
bfs(i);
}
return ans;
}
// int main(){
// int n ; cin >> n ; for(int i = 0 ; i < n ; i++ )cin >> x[i]>>y[i] ; cout << DistanceSum(n,x,y)<<endl;
// }
Compilation message
city.cpp:2:10: fatal error: city.h: No such file or directory
#include "city.h"
^~~~~~~~
compilation terminated.
