Submission #789970

#	Time	Username	Problem	Language	Result	Execution time	Memory
789970		GrindMachine	Street Lamps (APIO19_street_lamps)	C++17	0 / 100	5056 ms	1836 KiB

street_lamps

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct segtree {
    // https://codeforces.com/blog/entry/18051

    /*=======================================================*/

    struct data {
        int mx,sum;
    };

    data neutral = {-inf1,0};

    data merge(data &left, data &right) {
        data curr;
        curr.mx = max(left.mx,right.mx);
        curr.sum = left.sum + right.sum;
        return curr;
    }

    void create(int i, T v) {

    }

    void modify(int i, T v) {
        tr[i].mx = v;
        tr[i].sum ^= 1;
    }

    /*=======================================================*/

    int n;
    vector<data> tr;

    segtree() {

    }

    segtree(int siz) {
        init(siz);
    }

    void init(int siz) {
        n = siz;
        tr.assign(2 * n, neutral);
    }

    void build(vector<T> &a, int siz) {
        rep(i, siz) create(i + n, a[i]);
        rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    void pupd(int i, T v) {
        modify(i + n, v);
        for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    data query(int l, int r) {
        data resl = neutral, resr = neutral;

        for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) resl = merge(resl, tr[l++]);
            if (!(r & 1)) resr = merge(tr[r--], resr);
        }

        return merge(resl, resr);
    }
};

void solve(int test_case)
{
    int n,q; cin >> n >> q;
    vector<int> a(n+5);
    rep1(i,n){
        char ch; cin >> ch;
        a[i] = ch-'0';
    }

    set<array<int,3>> active;
    set<array<int,3>> segs;

    {
        int l = -1;
        rep1(i,n){
            if(!a[i]){
                if(l != -1){
                    active.insert({l,i-1,0});
                }

                l = -1;
            }
            else{
                if(l == -1){
                    l = i;
                }
            }
        }

        if(l != -1){
            active.insert({l,n,0});
        }
    }

    segtree<int> st(n+5);
    rep1(i,n){
        if(a[i]){
            st.pupd(i,0);
        }
    }

    auto get_seg = [&](int i){
        auto it = active.upper_bound({i+1,-1,-1});
        if(it == active.begin()) return active.end();
        else{
            it--;
            auto [l,r,t] = *it;
            if(l <= i and r >= i){
                return it;
            }
            else{
                return active.end();
            }
        }
    };

    rep1(id,q){
        string t; cin >> t;
        if(t == "toggle"){
            int i; cin >> i;
            a[i] ^= 1;
            st.pupd(i,id);

            if(!a[i]){
                // unset
                auto it = get_seg(i);
                assert(it != active.end());
                auto [l,r,t] = *it;
                segs.insert({l,r,id-t});
                active.erase(it);

                if(l <= i-1){
                    active.insert({l,i-1,id});
                }
                if(i+1 <= r){
                    active.insert({i+1,r,id});
                }
            }
            else{
                // set
                auto it1 = get_seg(i-1);
                auto it2 = get_seg(i+1);
                
                int l = -1, r = -1;

                if(it1 != active.end()){
                    auto curr = *it1;
                    active.erase(it1);
                    l = curr[0];                    
                    segs.insert({curr[0],curr[1],id-curr[2]});
                }

                if(it2 != active.end()){
                    auto curr = *it2;
                    active.erase(it2);
                    r = curr[1];
                    segs.insert({curr[0],curr[1],id-curr[2]});
                }

                if(l != -1 and r != -1){
                    active.insert({l,r,id});
                }
                else if(l != -1){
                    active.insert({l,i,id});
                }
                else if(r != -1){
                    active.insert({i,r,id});
                }
                else{
                    active.insert({i,i,id});
                }
            }
        }
        else{
            int l,r; cin >> l >> r;
            r--;
            int len = r-l+1;
            
            auto [mx,sum] = st.query(l,r);
            int ans = 0;

            if(sum == len){
                ans = id-mx;
            }

            for(auto [lx,rx,wx] : segs){
                if(lx <= l and rx >= r){
                    ans += wx;
                }
            }

            cout << ans << endl;
        }
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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