Submission #400138

#	Time	Username	Problem	Language	Result	Execution time	Memory
400138		dxz05	Street Lamps (APIO19_street_lamps)	C++14	60 / 100	712 ms	9524 KiB

street_lamps

#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define revall(x) (x).rbegin(), (x).rend()

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

typedef long long ll;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.00001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 5e5 + 3e2;
const int M = 2222;

string street;
int n, q;
char qch[N];
int ql[N], qr[N];

void Subtask_1(){
    vector<vector<int>> cnt(n, vector<int>(n, 0));
    for (int i = 0; i < n; i++){
        for (int j = i; j < n; j++){
            if (street[j] == '0') break;
            cnt[i][j] = 1;
        }
    }

    for (int i = 1; i <= q; i++){
        if (qch[i] == 't'){ // toggle
            street[ql[i]] ^= '0' ^ '1';
        } else { // query
            cout << cnt[ql[i]][qr[i]] << endl;
        }

        for (int l = 0; l < n; l++){
            for (int r = l; r < n; r++){
                if (street[r] == '0') break;
                cnt[l][r]++;
            }
        }

    }

    exit(0);

}

void Subtask_2(){
    vector<int> cnt(n + 1), last(n + 1);
    for (int i = 0; i < n; i++){
        if (street[i] == '1') cnt[i] = 1, last[i] = 1; else
            last[i] = -1;
    }

    for (int i = 1; i <= q; i++){
        if (qch[i] == 't'){
            int x = ql[i];
            if (street[x] == '1'){
                cnt[x] += i - last[x];
                last[x] = -1;
            } else {
                last[x] = i;
            }

            street[x] ^= '0' ^ '1';

        } else {
            int l = ql[i];
            cout << cnt[l] + (last[l] != -1 ? i - last[l] : 0) << endl;
        }
    }

    exit(0);
}

struct SegTree{
    int size = 1;
    vector<int> tree;
    void build(int v, int tl, int tr){
        if (tl == tr){
            tree[v] = (tl < n && street[tl] == '1' ? 0 : INF);
            return;
        }
        int tm = (tl + tr) >> 1;
        build(v + v, tl, tm);
        build(v + v + 1, tm + 1, tr);
        tree[v] = max(tree[v + v], tree[v + v + 1]);
    }

    void init(){
        while (size <= n) size *= 2;
        tree.resize(size * 2);
        build(1, 0, size - 1);
    }

    void update(int v, int tl, int tr, int pos, int val){
        if (tl == tr){
            tree[v] = val;
            return;
        }
        int tm = (tl + tr) >> 1;
        if (pos <= tm) update(v + v, tl, tm, pos, val); else
            update(v + v + 1, tm + 1, tr, pos, val);
        tree[v] = max(tree[v + v], tree[v + v + 1]);
    }

    void update(int pos, int val){
        update(1, 0, size - 1, pos, val);
    }

    int get(int v, int tl, int tr, int l, int r){
        if (l <= tl && tr <= r) return tree[v];
        if (tl > r || tr < l) return 0;
        int tm = (tl + tr) >> 1;
        return max(get(v + v, tl, tm, l, r), get(v + v + 1, tm + 1, tr, l, r));
    }

    int get(int l, int r){
        return get(1, 0, size - 1, l, r);
    }

};

void Subtask_3(){
    SegTree st;
    st.init();
    for (int i = 1; i <= q; i++){
        if (qch[i] == 't'){
            st.update(ql[i], i);
        } else {
            cout << max(0, i - st.get(ql[i], qr[i])) << endl;
        }
     //   for (int j = 0; j < n; j++) cout << st.get(j, j) << ' '; cout << endl;
    }

    exit(0);
}

void solve(int TC) {
    cin >> n >> q >> street;

    bool ok2 = true;
    for (int i = 1; i <= q; i++){
        string t;
        cin >> t >> ql[i];
        qch[i] = t[0];
        ql[i]--;
        if (qch[i] == 'q') {
            cin >> qr[i];
            qr[i] -= 2;
            ok2 &= ql[i] == qr[i];
        }
    }

    if (n <= 100 && q <= 100){
        Subtask_1();
    }

    if (ok2){
        Subtask_2();
    }

    Subtask_3();

}


int main() {
    startTime = clock();
    cin.tie(nullptr); cout.tie(nullptr);
    ios_base::sync_with_stdio(false);

    bool llololcal = false;
#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    llololcal = true;
#endif

    int TC = 1;
    //cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

    if (llololcal) cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;

    return 0;
}

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