Submission #465885

#	Time	Username	Problem	Language	Result	Execution time	Memory
465885		alextodoran	Street Lamps (APIO19_street_lamps)	C++17	100 / 100	2779 ms	218608 KiB

street_lamps

/**
 ____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|

**/

#include <bits/stdc++.h>

#pragma GCC target ("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

using namespace std;

typedef long long ll;

const int N_MAX = 300000;
const int Q_MAX = 300000;

const int BUFFER_SIZE = 200000;

char buffer[BUFFER_SIZE];
int bpos = BUFFER_SIZE - 1;

char read_char ()
{
    bpos++;
    if(bpos == BUFFER_SIZE)
    {
        fread(buffer, sizeof(char), BUFFER_SIZE, stdin);
        bpos = 0;
    }
    return buffer[bpos];
}

bool isDigit[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

int read_int ()
{
    char c;
    while(!isDigit[c = read_char()]);
    int ans = 0;
    do
    {
        ans = ans * 10 + c - '0';
    }
    while(isDigit[c = read_char()]);
    return ans;
}

char bufferOut[BUFFER_SIZE];
int opos = -1;

void print_buffer ()
{
    fwrite(bufferOut, sizeof(char), opos + 1, stdout);
}

void print_char (char c)
{
    if(opos == BUFFER_SIZE - 1)
    {
        print_buffer();
        opos = -1;
    }
    opos++;
    bufferOut[opos] = c;
}

void print_int (int a)
{
    if(a == 0)
    {
        print_char('0');
        return;
    }
    int a1 = a, p10 = 1;
    while(a1)
    {
        p10 *= 10;
        a1 /= 10;
    }
    p10 /= 10;
    while(p10)
    {
        print_char(a / p10 % 10 + '0');
        a %= p10;
        p10 /= 10;
    }
}

int n, q;

bool light[N_MAX + 2];
bool old[N_MAX + 2];

int L[Q_MAX + 2];
int R[Q_MAX + 2];
bool full[Q_MAX + 2];

struct Query
{
    bool type;
    int pos;
    int l, r;
};

Query queries[Q_MAX + 2];

struct SGTNode
{
    int len;
    int pref;
    int suff;
};

SGTNode join (const SGTNode &u, const SGTNode &v)
{
    return SGTNode
    {
        u.len + v.len,
        (u.pref == u.len ? u.len + v.pref : u.pref),
        (v.suff == v.len ? v.len + u.suff : v.suff)
    };
}

SGTNode SGT[N_MAX * 4 + 2];

void build (int node, int l, int r)
{
    if(l == r)
    {
        SGT[node] = SGTNode{1, light[l], light[l]};
        return;
    }

    int mid = (l + r) / 2;
    int lSon = node * 2, rSon = node * 2 + 1;

    build(lSon, l, mid);
    build(rSon, mid + 1, r);

    SGT[node] = join(SGT[lSon], SGT[rSon]);
}
void build ()
{
    build(1, 1, n);
}

void update (int node, int l, int r, int upos)
{
    if(l == r)
    {
        SGT[node].pref = 1 - SGT[node].pref;
        SGT[node].suff = 1 - SGT[node].suff;
        return;
    }

    int mid = (l + r) / 2;
    int lSon = node * 2, rSon = node * 2 + 1;

    if(upos <= mid)
        update(lSon, l, mid, upos);
    else
        update(rSon, mid + 1, r, upos);

    SGT[node] = join(SGT[lSon], SGT[rSon]);
}
void update (int upos)
{
    update(1, 1, n, upos);
}

SGTNode query (int node, int l, int r, int ql, int qr)
{
    if(ql <= l && r <= qr)
        return SGT[node];

    int mid = (l + r) / 2;
    int lSon = node * 2, rSon = node * 2 + 1;

    if(ql <= mid && mid + 1 <= qr)
        return join(query(lSon, l, mid, ql, qr), query(rSon, mid + 1, r, ql, qr));
    else if(ql <= mid)
        return query(lSon, l, mid, ql, qr);
    else
        return query(rSon, mid + 1, r, ql, qr);
}
SGTNode query (int ql, int qr)
{
    if(ql > qr)
        return SGTNode{0, 0, 0};
    return query(1, 1, n, ql, qr);
}

vector <int> BITpos[(N_MAX + 1) + 2];

vector <int> BIT[(N_MAX + 1) + 2];

void BITupdateSim (int x, int y)
{
    for(int i = x; i <= y; i += i & -i)
        for(int j = y; j >= i; j -= j & -j)
            BITpos[i].push_back(j);
}

void BITquerySim (int x, int y)
{
    for(int i = x; i >= 1; i -= i & -i)
        for(int j = y; j <= n + 1; j += j & -j)
            BITpos[i].push_back(j);
}

void compress (int i)
{
    sort(BITpos[i].begin(), BITpos[i].end());
    BITpos[i].resize(unique(BITpos[i].begin(), BITpos[i].end()) - BITpos[i].begin());
    BIT[i].resize((int) BITpos[i].size() + 1);
}
int getPos (int i, int y)
{
    int l = 0, r = (int) BITpos[i].size();
    while(l < r)
    {
        int mid = (l + r) / 2;
        if(BITpos[i][mid] < y)
            l = mid + 1;
        else
            r = mid;
    }
    return l + 1;
}

void BITupdate (int x, int y, int uval)
{
    for(int i = x; i <= y; i += i & -i)
        for(int j = getPos(i, y); j >= 1; j -= j & -j)
            BIT[i][j] += uval;
}

int BITquery (int x, int y)
{
    int answer = 0;
    for(int i = x; i >= 1; i -= i & -i)
        for(int j = getPos(i, y); j <= (int) BITpos[i].size(); j += j & -j)
            answer += BIT[i][j];
    return answer;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    n = read_int();
    q = read_int();

    for(int i = 1; i <= n; i++)
        light[i] = old[i] = (read_char() == '1');
    read_char();

    build();

    for(int i = 1; i <= n; i++)
        if(light[i] == true)
        {
            int j = i;
            while(j < n && light[j + 1] == true)
                j++;

            BITupdateSim(i, j + 1);

            i = j;
        }

    for(int qi = 1; qi <= q; qi++)
    {
        if(read_char() == 't')
        {
            queries[qi].type = 0;

            int upos = read_int();

            queries[qi].pos = upos;

            int lLen = query(1, upos - 1).suff;
            int rLen = query(upos + 1, n).pref;

            L[qi] = upos - lLen;
            R[qi] = upos + 1 + rLen;

            int l = L[qi];
            int r = R[qi];

            if(light[upos] == true)
            {
                BITupdateSim(l, r);
                BITupdateSim(l, upos);
                BITupdateSim(upos + 1, r);
            }

            light[upos] = !light[upos];
            update(upos);

            if(light[upos] == true)
            {
                BITupdateSim(l, r);
                BITupdateSim(l, upos);
                BITupdateSim(upos + 1, r);
            }

        }
        else
        {
            queries[qi].type = 1;

            int l = read_int();
            int r = read_int();

            queries[qi].l = l;
            queries[qi].r = r;

            BITquerySim(l, r);

            full[qi] = (query(l, r - 1).pref == r - l);
        }
    }

    for(int i = 1; i <= n + 1; i++)
        compress(i);

    /// ======================================================================================

    for(int i = 1; i <= n; i++)
        light[i] = old[i];

    for(int i = 1; i <= n; i++)
        if(light[i] == true)
        {
            int j = i;
            while(j < n && light[j + 1] == true)
                j++;

            BITupdate(i, j + 1, + q);

            i = j;
        }

    for(int qi = 1; qi <= q; qi++)
    {
        if(queries[qi].type == 0)
        {
            int upos = queries[qi].pos;

            int l = L[qi];
            int r = R[qi];

            if(light[upos] == true)
            {
                BITupdate(l, r, - (q - qi));
                BITupdate(l, upos, + (q - qi));
                BITupdate(upos + 1, r, + (q - qi));
            }

            light[upos] = !light[upos];

            if(light[upos] == true)
            {
                BITupdate(l, r, + (q - qi));
                BITupdate(l, upos, - (q - qi));
                BITupdate(upos + 1, r, - (q - qi));
            }

        }
        else
        {
            int l = queries[qi].l;
            int r = queries[qi].r;

            int answer = BITquery(l, r);

            if(full[qi] == true)
                answer -= (q - qi);

            print_int(answer);
            print_char('\n');
        }
    }

    print_buffer();

    return 0;
}

Compilation message (stderr)

street_lamps.cpp: In function 'int read_int()':
street_lamps.cpp:59:22: warning: array subscript has type 'char' [-Wchar-subscripts]
   59 |     while(!isDigit[c = read_char()]);
      |                    ~~^~~~~~~~~~~~~
street_lamps.cpp:65:21: warning: array subscript has type 'char' [-Wchar-subscripts]
   65 |     while(isDigit[c = read_char()]);
      |                   ~~^~~~~~~~~~~~~
street_lamps.cpp: In function 'char read_char()':
street_lamps.cpp:32:14: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |         fread(buffer, sizeof(char), BUFFER_SIZE, stdin);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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