Submission #349526

#	Time	Username	Problem	Language	Result	Execution time	Memory
349526		ACmachine	Seats (IOI18_seats)	C++17	100 / 100	1126 ms	177260 KiB

seats

#include "seats.h"

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T, typename U> using ordered_map = tree<T, U, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<str> vstr;

#define FOR(i,j,k,in) for(int i=(j); i < (k);i+=in)
#define FORD(i,j,k,in) for(int i=(j); i >=(k);i-=in)
#define REP(i,b) FOR(i,0,b,1)
#define REPD(i,b) FORD(i,b,0,1)
#define pb push_back 
#define mp make_pair
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define rsz resize 
#define MANY_TESTS int tcase; cin >> tcase; while(tcase--)
	
const double EPS = 1e-9;
const int MOD = 1e9+7; // 998244353;
const ll INFF = 1e18;
const int INF = 1e9;
const ld PI = acos((ld)-1);
const vi dy = {0, 1, 1, 1, 0, -1, -1, -1};
const vi dx = {-1, -1, 0, 1, 1, 1, 0, -1};

#ifdef DEBUG
#define DBG if(1)
#else
#define DBG if(0)
#endif

#define dbg(x) cout << "(" << #x << " : " << x << ")" << endl;
// ostreams
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "[" << par.first << ";" << par.second << "]"; return out;}
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for( const auto &x:cont) out << x << ", "; out << "}"; return out; }
template<class T>
ostream& operator<<(ostream& out, const vector<T> &v){ out << "[";  REP(i, v.size()) out << v[i] << ", ";  out << "]"; return out;}
// istreams
template<class T>
istream& operator>>(istream& in, vector<T> &v){ for(auto &x : v) in >> x; return in; }
template<class T, class U>
istream& operator>>(istream& in, pair<T, U> &p){ in >> p.ff >> p.ss; return in; }
//searches
template<typename T, typename U>
T bsl(T lo, T hi, U f){ hi++; T mid; while(lo < hi){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid+1; } return lo; }
template<typename U>
double bsld(double lo, double hi, U f, double p = 1e-9){ int r = 3 + (int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? hi = mid : lo = mid; } return (lo + hi)/2; }
template<typename T, typename U>
T bsh(T lo, T hi, U f){ lo--; T mid; while(lo < hi){ mid = (lo + hi + 1)/2; f(mid) ? lo = mid : hi = mid-1; } return lo; }
template<typename U>
double bshd(double lo, double hi, U f, double p = 1e-9){ int r = 3+(int)log2((hi - lo)/p); double mid; while(r--){ mid = (lo + hi)/2; f(mid) ? lo = mid : hi = mid; } return (lo + hi)/2; }
// some more utility functions
template<typename T>
pair<T, int> get_min(vector<T> &v){ typename vector<T> :: iterator it = min_element(v.begin(), v.end()); return mp(*it, it - v.begin());}
template<typename T>
pair<T, int> get_max(vector<T> &v){ typename vector<T> :: iterator it = max_element(v.begin(), v.end()); return mp(*it, it - v.begin());}        
template<typename T> bool ckmin(T& a, const T& b){return b < a ? a = b , true : false;}
template<typename T> bool ckmax(T& a, const T& b){return b > a ? a = b, true : false;}

struct node{
    int ans = INF; int count = 0;
    int total_balance = INF;
    void apply(int l, int r, int val){
        ans = val; count = 1;
        total_balance = ans;
    }
};
struct segtree{
    segtree(){}
    node comb(node const &a, node const &b){
        node res;
        int nrans = a.total_balance + b.ans;
        res.total_balance = a.total_balance + b.total_balance;
        if(a.ans < nrans){
            res.ans = a.ans;
            res.count = a.count;
        }
        else if(a.ans > nrans){
            res.ans = nrans;
            res.count = b.count;
        }
        else if(a.ans == nrans){
            res.ans = a.ans;
            res.count = a.count + b.count;
        }
        return res;
    } 
    void push(int l, int r, int v){ 
    }
    int sz;
    vector<node> tree; 
    segtree(int _sz){ // tree is resized to default values set in node
        sz = 1; while(sz < _sz) sz<<=1;
        tree.resize(2*sz); 
    } 
    void build(vector<node> &init){
        for(int i = 0; i < sz; ++i) 
            if(i < init.size())
                tree[i+sz] = init[i];
        for(int i = sz-1; i > 0; --i)
            tree[i] = comb(tree[i<<1], tree[i<<1|1]);
    } 
    node query(int l, int r){return query0(l, r, 0, sz, 1);} 
    node query0(int l, int r, int beg, int end, int v){ 
        if(beg >= l && end <= r)
            return tree[v];
        push(beg, end, v);
        int mid = (beg + end) >> 1;
        node res;
        if(beg >= r || mid <= l) res = query0(l, r, mid, end, v<<1|1); //[beg, mid]
        else if(mid >= r || end <= l) res = query0(l, r, beg, mid, v<<1);
        else res = comb(query0(l, r, beg, mid, v<<1), query0(l, r, mid, end, v<<1|1));
        return res;
    } 
    template<typename... T>
    void upd(int l, int r, T ...args){upd0(l, r, 0, sz, 1, args...);}
    template<typename... T>
    void upd0(int l, int r, int beg, int end, int v, T ...args){
        if(beg >= r || end <= l)
            return;
        if(beg >= l && end <= r){
            tree[v].apply(beg, end, args...);
            return;
        }
        push(beg, end, v);
        int mid = (beg + end) >> 1;
        upd0(l, r, beg, mid, v<<1, args...);
        upd0(l, r, mid, end, v<<1|1, args...);
        tree[v] = comb(tree[v<<1], tree[v<<1|1]);
    } 
};

vector<int> r, c;
vector<vector<int>> grid;
vector<vector<int>> bal;
segtree st;
int h, w;
void recalc_balance(int y, int x){
    if(y < 0 || y >= h || x < 0 || x >= w) return;
    int nbal = 0;
    array<int, 4> bf = {1, 1, 1, 1};
    REP(sm, 8){
        int ny = y + dy[sm];
        int nx = x + dx[sm];
        int ch = 0;
        if(ny < 0 || ny >= h || nx < 0 || nx >= w) continue;
        if(grid[ny][nx] < grid[y][x]) ch = 1;
        if(sm >= 0 && sm <= 2) bf[0] += ch;
        if(sm >= 2 && sm <= 4) bf[1] += ch;
        if(sm >= 4 && sm <= 6) bf[2] += ch;
        if((sm >= 6 && sm <= 7) || sm == 0) bf[3] += ch;
    }
    REP(j, 4){
        if(bf[j]%2 == 1){
            nbal++;
        }
        else{
            nbal--;
        }
    }
    bal[y][x] = nbal; 
}
void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
    r = R;
    c = C;
    h = H; w = W;
    grid = vector<vector<int>>(h, vector<int>(w));     
    REP(i, h * w){
        grid[r[i]][c[i]] = i;
    }
    bal = vector<vector<int>>(h, vector<int>(w));
    REP(i, h){
        REP(j, w) 
            recalc_balance(i, j);
    }
    st = segtree(h * w);
    vector<node> init(h * w);
    REP(i, h * w){
        node tmp;
        tmp.ans = bal[r[i]][c[i]];
        tmp.count = 1;
        tmp.total_balance = bal[r[i]][c[i]];
        init[i] = tmp;
    }
    st.build(init); 
}
int swap_seats(int a, int b) {
    swap(r[a], r[b]);
    swap(c[a], c[b]);
    swap(grid[r[a]][c[a]], grid[r[b]][c[b]]);
    FOR(ddy, -1, 2, 1){
        FOR(ddx, -1, 2, 1){
            int ny = r[a] + ddy;
            int nx = c[a] + ddx;
            if(!(ny < 0 || ny >= h || nx < 0 || nx >= w)){
                recalc_balance(ny, nx);
                int e = grid[ny][nx];
                st.upd(e, e + 1, bal[ny][nx]);
            }
            ny = r[b] + ddy;
            nx = c[b] + ddx;
            if(!(ny < 0 || ny >= h || nx < 0 || nx >= w)){
                recalc_balance(ny, nx);
                int e = grid[ny][nx];
                st.upd(e, e + 1, bal[ny][nx]);
            }
        }
    }
    auto no = st.query(0, h * w);
    return no.count;
}

Compilation message (stderr)

seats.cpp: In member function 'void segtree::build(std::vector<node>&)':
seats.cpp:123:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<node>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |             if(i < init.size())
      |                ~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 20 / 20
• Subtask 4: 6 / 6
• Subtask 5: 33 / 33
• Subtask 6: 30 / 30