Submission #249023

#	Time	Username	Problem	Language	Result	Execution time	Memory
249023		SamAnd	Street Lamps (APIO19_street_lamps)	C++17	60 / 100	1129 ms	16724 KiB

street_lamps

#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 300005;

struct ban
{
    char ty;
    int x, y;
};

int n_, q_;
char s_[N];
ban a_[N];

void ka()
{
    cin >> n_ >> q_;
    cin >> s_;
    for (int i = 0; i < q_; ++i)
    {
        char tyy[20];
        cin >> tyy;
        a_[i].ty = tyy[0];
        if (tyy[0] == 't')
            cin >> a_[i].x;
        else
            cin >> a_[i].x >> a_[i].y;
    }
}

namespace solv1
{
    const int N = 102;

    int n, q;
    char a[N][N], aa[N];
    int p[N][N];

    void cntp(int i)
    {
        for (int j = 1; j <= n; ++j)
        {
            p[i][j] = p[i][j - 1];
            if (a[i][j] == '1')
                ++p[i][j];
        }
    }

    void solv()
    {
        n = n_;
        q = q_;
        for (int i = 0; i < n; ++i)
            aa[i] = s_[i];
        for (int j = 1; j <= n; ++j)
            a[0][j] = aa[j - 1];
        cntp(0);
        for (int i = 1; i <= q; ++i)
        {
            for (int j = 1; j <= n; ++j)
            {
                a[i][j] = a[i - 1][j];
            }
            char ty;
            ty = a_[i - 1].ty;
            if (ty == 'q')
            {
                int l, r;
                l = a_[i - 1].x;
                r = a_[i - 1].y;
                --r;
                int ans = 0;
                for (int ii = 0; ii < i; ++ii)
                {
                    if (p[ii][r] - p[ii][l - 1] == (r - l + 1))
                        ++ans;
                }
                cout << ans << endl;
            }
            else
            {
                int x;
                x = a_[i - 1].x;
                if (a[i][x] == '0')
                    a[i][x] = '1';
                else
                    a[i][x] = '0';
            }
            cntp(i);
        }
    }
};

namespace solv2
{
    const int N = 300005;

    int n, q;
    char a[N];

    int ans[N];
    int t[N];

    void solv()
    {
        n = n_;
        q = q_;
        for (int i = 1; i <= n; ++i)
        {
            a[i] = s_[i - 1];
            if (a[i] == '1')
            {
                t[i] = 0;
            }
            else
                t[i] = -1;
        }
        for (int j = 1; j <= q; ++j)
        {
            char ty;
            ty = a_[j - 1].ty;
            if (ty == 'q')
            {
                int l, r;
                l = a_[j - 1].x;
                r = a_[j - 1].y;
                if (t[l] == -1)
                    cout << ans[l] << endl;
                else
                    cout << ans[l] + (j - t[l]) << endl;
            }
            else
            {
                int i;
                i = a_[j - 1].x;
                if (a[i] == '0')
                {
                    a[i] = '1';
                    t[i] = j;
                }
                else
                {
                    a[i] = '0';
                    ans[i] += (j - t[i]);
                    t[i] = -1;
                }
            }
        }
    }
};

namespace solv3
{
    const int N = 300005;

    int n, q;
    char a[N];

    int t[N * 4];
    void ubd(int tl, int tr, int x, int y, int pos)
    {
        if (tl == tr)
        {
            t[pos] = y;
            return;
        }
        int m = (tl + tr) / 2;
        if (x <= m)
            ubd(tl, m, x, y, pos * 2);
        else
            ubd(m + 1, tr, x, y, pos * 2 + 1);
        t[pos] = max(t[pos * 2], t[pos * 2 + 1]);
    }
    int qry(int tl, int tr, int l, int r, int pos)
    {
        if (tl == l && tr == r)
            return t[pos];
        int m = (tl + tr) / 2;
        if (r <= m)
            return qry(tl, m, l, r, pos * 2);
        if (l > m)
            return qry(m + 1, tr, l, r, pos * 2 + 1);
        return max(qry(tl, m, l, m, pos * 2), qry(m + 1, tr, m + 1, r, pos * 2 + 1));
    }

    void solv()
    {
        n = n_;
        q = q_;
        for (int i = 1; i <= n; ++i)
        {
            a[i] = s_[i - 1];
            if (a[i] == '0')
                ubd(1, n, i, N, 1);
            else
                ubd(1, n, i, 0, 1);
        }
        for (int i = 1; i <= q; ++i)
        {
            char ty;
            ty = a_[i - 1].ty;
            if (ty == 'q')
            {
                int l, r;
                l = a_[i - 1].x;
                r = a_[i - 1].y;
                --r;
                int j = qry(1, n, l, r, 1);
                if (j == N)
                    cout << 0 << endl;
                else
                    cout << i - j << endl;
            }
            else
            {
                int x;
                x = a_[i - 1].x;
                ubd(1, n, x, i, 1);
            }
        }
    }
};

int main()
{
    #ifdef SOMETHING
    freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    #endif // SOMETHING
    //ios_base::sync_with_stdio(false), cin.tie(0);
    ka();
    if (n_ <= 100 && q_ <= 100)
    {
        solv1::solv();
        return 0;
    }
    bool z2 = true;
    for (int i = 0; i < q_; ++i)
    {
        if (a_[i].ty == 'q')
        {
            if (a_[i].y - a_[i].x != 1)
            {
                z2 = false;
                break;
            }
        }
    }
    if (z2)
    {
        solv2::solv();
    }
    else
    {
        solv3::solv();
    }
    return 0;
}

//while ((double)clock() / CLOCKS_PER_SEC <= 0.9){}

Compilation message (stderr)

street_lamps.cpp: In function 'void solv2::solv()':
street_lamps.cpp:132:24: warning: variable 'r' set but not used [-Wunused-but-set-variable]
                 int l, r;
                        ^

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