Submission #430816

#	Time	Username	Problem	Language	Result	Execution time	Memory
430816		MarcoMeijer	Ideal city (IOI12_city)	C++14	100 / 100	157 ms	15940 KiB

city

#include <bits/stdc++.h>
using namespace std;

// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e9
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }

const ll MOD = 1e9;

const int dx[] = {0,1,0,-1};
const int dy[] = {1,0,-1,0};

const int MX = 1e5+10;
const int N = 1<<17;


struct maxSeg {
    int seg[N*2], laz[N*2];
    void build(int p=1, int l=0, int r=N-1) {
        seg[p] = -1;
        laz[p] = -N;
        if(l == r)
            return;
        int m = (l+r)/2;
        build(p*2,l,m);
        build(p*2+1,m+1,r);
    }
    void setVertex(int p, int v) {
        seg[p] = v;
        laz[p] = v;
    }
    void push(int p) {
        if(laz[p] == -N) return;
        setVertex(p*2,laz[p]);
        setVertex(p*2+1,laz[p]);
        laz[p] = -N;
    }
    void set(int i, int j, int v, int p=1, int l=0, int r=N-1) {
        if(j < l || i > r) return;
        if(i <= l && j >= r) {
            setVertex(p,v);
            return;
        }
        push(p);
        int m=(l+r)/2;
        set(i,j,v,p*2  ,l  ,m);
        set(i,j,v,p*2+1,m+1,r);
        seg[p] = max(seg[p*2], seg[p*2+1]);
    }
    int get(int i, int j, int p=1, int l=0, int r=N-1) {
        if(j < l || i > r) return -1;
        if(i <= l && j >= r) return seg[p];
        push(p);
        int m=(l+r)/2;
        int a=get(i,j,p*2,l,m);
        if(a != -1) return a;
        return get(i,j,p*2+1,m+1,r);
    }
} seg;

vi atY[MX];

int w[MX], nodes;
int L[MX], R[MX];
vi adj[MX];

int n;
ll res;
void dfs(int u, int p) {
    FOR(v,adj[u]) {
        if(v == p) continue;
        dfs(v,u);
        w[u] += w[v];
        res += ll(n-w[v]) * (ll)w[v];
        res %= MOD;
    }
}

int DistanceSum(int N, int *X, int *Y) {
    n=N;

    // coördinate compression
    int minX, minY;
    minX = minY = 1<<31-1;
    RE(i,n) minX=min(minX,X[i]), minY=min(minY,Y[i]);
    RE(i,n) X[i]-=minX-1, Y[i]-=minY-1;

    res = 0;

    RE(_,2) {
        // reset graph
        RE(i,nodes) w[i] = 0;
        RE(i,nodes) adj[i].clear(); nodes = 0;

        // fill atY
        RE(i,MX) atY[i].clear();
        RE(i,n) atY[Y[i]].pb(X[i]);
        RE(i,MX) sort(all(atY[i]));
        RE(i,MX) atY[i].pb(INF);

        seg.build();
        RE(i,MX) {
            int nodesCopy = nodes;

            // link the nodes
            int lastX = -INF, groupSize = 0;
            FOR(x,atY[i]) {
                if(lastX + 1 != x && groupSize != 0) {
                    // new group
                    int l = lastX - groupSize + 1;
                    int r = lastX;
                    int u = nodes++;
                    vi changed;
                    while(true) {
                        int v = seg.get(l,r);
                        if(v == -1) break;
                        adj[u].pb(v);
                        adj[v].pb(u);
                        seg.set(L[v],R[v],-1);
                        changed.pb(v);
                    }
                    FOR(v,changed)
                        seg.set(L[v],R[v],v);
                    w[u] = groupSize;
                    groupSize = 0;
                }
                lastX = x;
                groupSize++;
            }
            
            // update the segment tree
            seg.set(0,N-1,-1);
            lastX = -INF, groupSize = 0;
            FOR(x,atY[i]) {
                if(lastX + 1 != x && groupSize != 0) {
                    // new group
                    int l = lastX - groupSize + 1;
                    int r = lastX;
                    int u = nodesCopy++;
                    seg.set(l,r,u);
                    L[u] = l, R[u] = r;
                    groupSize = 0;
                }
                lastX = x;
                groupSize++;
            }
        }

        dfs(0,0);

        swap(X,Y);
    }

    return res;
}

Compilation message (stderr)

city.cpp: In function 'int DistanceSum(int, int*, int*)':
city.cpp:118:24: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  118 |     minX = minY = 1<<31-1;
      |                      ~~^~
city.cpp:15:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   15 | #define REP(a,b,c) for(int a=int(b); a<int(c); a++)
      |                    ^~~
city.cpp:16:17: note: in expansion of macro 'REP'
   16 | #define RE(a,c) REP(a,0,c)
      |                 ^~~
city.cpp:127:9: note: in expansion of macro 'RE'
  127 |         RE(i,nodes) adj[i].clear(); nodes = 0;
      |         ^~
city.cpp:127:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  127 |         RE(i,nodes) adj[i].clear(); nodes = 0;
      |                                     ^~~~~

• Subtask 1: 11 / 11
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 45 / 45