Submission #1106214

#	Time	Username	Problem	Language	Result	Execution time	Memory
1106214		zNatsumi	Street Lamps (APIO19_street_lamps)	C++17	20 / 100	4456 ms	524288 KiB

street_lamps

#include <bits/stdc++.h>

using namespace std;

typedef tuple<string, int, int> Que;

const int N = 3e5 + 10,
          INF = 1e9;

int n, q;
string s;
Que query[N];

struct BIT2D{
  vector<int> node[N], bit[N];

  void fake_upd(int x, int y){
    for(int i = x; i <= n; i += i & -i)
      for(int j = y; j <= n; j += j & -j)
        node[i].push_back(j);
  }
  void fake_update(int x, int y, int u, int v){
    fake_upd(x, y);
    fake_upd(x, v + 1);
    fake_upd(u + 1, y);
    fake_upd(u + 1, v + 1);
  }
  void fake_get(int x, int y){
    for(int i = x; i > 0; i -= i & -i)
      for(int j = y; j > 0; j -= j & -j)
        node[i].push_back(j);
  }

  void build(){
    for(int i = 1; i <= n; i++) if(node[i].size()){
      sort(node[i].begin(), node[i].end());
      node[i].erase(unique(node[i].begin(), node[i].end()), node[i].end());
      bit[i].assign(node[i].size() + 1, 0);
    }
  }

  void upd(int x, int y, int val){
    for(int i = x; i <= n; i += i & -i)
      for(int j = lower_bound(node[i].begin(), node[i].end(), y) - node[i].begin() + 1; j <= node[i].size(); j += j & -j)
        bit[i][j - 1] += val;
  }

  void update(int x, int y, int u, int v, int val){
    upd(x, y, val);
    upd(x, v + 1, -val);
    upd(u + 1, y, -val);
    upd(u + 1, v + 1, val);
  }
  int get(int x, int y){
    int res = 0;
    for(int i = x; i > 0; i -= i & -i)
      for(int j = lower_bound(node[i].begin(), node[i].end(), y) - node[i].begin() + 1; j > 0; j -= j & -j)
        res += bit[i][j - 1];
    return res;
  }
} bit;

struct SegTree{
  int st[N << 2], lz[N << 2];

  void build(int tl, int tr, int i){
    lz[i] = -1;
    if(tl == tr){
      st[i] = (s[tl] == '1' ? 0 : INF);
      return;
    }
    int tm = tl + tr >> 1;
    build(tl, tm, i<<1);
    build(tm + 1, tr, i<<1|1);
    st[i] = max(st[i<<1], st[i<<1|1]);
  }
  void push(int i){
    if(lz[i] == -1) return;
    st[i<<1] = st[i<<1|1] = lz[i<<1] = lz[i<<1|1] = lz[i];
    lz[i] = -1;
  }

  void update(int l, int r, int val, int tl, int tr, int i){
    if(r < tl || tr < l || l > r) return;
    if(l <= tl && tr <= r){
      st[i] = val;
      lz[i] = val;
      return;
    }
    if(tl != tr) push(i);
    int tm = tl + tr >> 1;
    update(l, r, val, tl, tm, i<<1);
    update(l, r, val, tm + 1, tr, i<<1|1);
    st[i] = max(st[i<<1], st[i<<1|1]);
  }

  int get(int l, int r, int tl, int tr, int i){
    if(r < tl || tr < l || l > r) return 0;
    if(l <= tl && tr <= r) return st[i];
    if(tl != tr) push(i);
    int tm = tl + tr >> 1;
    return max(get(l, r, tl, tm, i<<1), get(l, r, tm + 1, tr, i<<1|1));
  }
} it;

void init(){
  set<int> pos0;
  for(int i = 1; i <= n; i++) if(s[i] == '0') pos0.insert(i);
  pos0.insert(0); pos0.insert(n + 1);

  string tmp = s;

  for(int t = 1; t <= q; t++){
    auto [ty, x, y] = query[t];

    if(ty == "toggle"){
      if(s[x] == '0'){
        auto i = pos0.find(x);
        int l = *prev(i) + 1, r = *next(i) - 1;

        s[x] = '1';

        if(l <= *i - 1) bit.fake_update(l, l, *i - 1, *i - 1);
        if(*i + 1 <= r) bit.fake_update(*i + 1, *i + 1, r, r);

        pos0.erase(x);
      }else{
        s[x] = '0';
        pos0.insert(x);

        auto i = pos0.find(x);
        int l = *prev(i) + 1, r = *next(i) - 1;

        bit.fake_update(l, l, r, r);
      }
    }else{
      bit.fake_get(x, y);
    }
  }
  bit.build();
  s = tmp;
}

void solve(){
  set<int> pos0;
  for(int i = 1; i <= n; i++) if(s[i] == '0') pos0.insert(i);
  pos0.insert(0); pos0.insert(n + 1);

  it.build(1, n, 1);

  for(int t = 1; t <= q; t++){
    auto [ty, x, y] = query[t];

    if(ty == "toggle"){
      if(s[x] == '0'){
        auto i = pos0.find(x);
        int l = *prev(i) + 1, r = *next(i) - 1;

        s[x] = '1';

        if(l <= *i - 1) bit.update(l, l, *i - 1, *i - 1, t - it.get(l, *i - 1, 1, n, 1));
        if(*i + 1 <= r) bit.update(*i + 1, *i + 1, r, r, t - it.get(*i + 1, r, 1, n, 1));
        it.update(l, r, t, 1, n, 1);

        pos0.erase(x);
      }else{
        s[x] = '0';
        pos0.insert(x);

        auto i = pos0.find(x);
        int l = *prev(i) + 1, r = *next(i) - 1;

        bit.update(l, l, r, r, t - it.get(l, r, 1, n, 1));
        it.update(l, r, t, 1, n, 1);
        it.update(*i, *i, INF, 1, n, 1);
      }
    }else{
      auto tmp = t - it.get(x, y, 1, n, 1);
      cout << bit.get(x, y) + (tmp >= 0 ? tmp : 0) << "\n";
    }
  }
}

int32_t main(){
  cin.tie(0)->sync_with_stdio(0);
  #define task "test"
  if(fopen(task ".inp", "r")){
    freopen(task ".inp", "r", stdin);
    freopen(task ".out", "w", stdout);
  }
  cin >> n >> q >> s;
  s = " " + s;

  for(int i = 1; i <= q; i++){
    string ty; cin >> ty;
    if(ty == "toggle"){
      int x; cin >> x;
      query[i] = Que(ty, x, -1);
    }else{
      int x, y; cin >> x >> y;
      query[i] = Que(ty, x, y - 1);
    }
  }
  init();
  solve();
  cerr << "TIME 1: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";

  return 0;
}

Compilation message (stderr)

street_lamps.cpp: In member function 'void BIT2D::upd(int, int, int)':
street_lamps.cpp:44:91: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |       for(int j = lower_bound(node[i].begin(), node[i].end(), y) - node[i].begin() + 1; j <= node[i].size(); j += j & -j)
      |                                                                                         ~~^~~~~~~~~~~~~~~~~
street_lamps.cpp: In member function 'void SegTree::build(int, int, int)':
street_lamps.cpp:72:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   72 |     int tm = tl + tr >> 1;
      |              ~~~^~~~
street_lamps.cpp: In member function 'void SegTree::update(int, int, int, int, int, int)':
street_lamps.cpp:91:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   91 |     int tm = tl + tr >> 1;
      |              ~~~^~~~
street_lamps.cpp: In member function 'int SegTree::get(int, int, int, int, int)':
street_lamps.cpp:101:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  101 |     int tm = tl + tr >> 1;
      |              ~~~^~~~
street_lamps.cpp: In function 'int32_t main()':
street_lamps.cpp:188:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  188 |     freopen(task ".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
street_lamps.cpp:189:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  189 |     freopen(task ".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20