Submission #202203

#	Time	Username	Problem	Language	Result	Execution time	Memory
202203		stefdasca	Election (BOI18_election)	C++14	0 / 100	8 ms	504 KiB

election

#include<bits/stdc++.h>
#define god dimasi5eks
#pragma GCC optimize("O3")
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define mod 1000000007
#define dancila 3.14159265359
#define eps 1e-9

using namespace std;

typedef long long ll;

int n, q;

string s;

int sp[500002], sp2[500002], lstT[500002], lstDT[500002], sT[500002];

int aint[2000002], aint2[2000002];
int wh[2000002], wh2[2000002];

void build(int nod, int st, int dr)
{
    if(st == dr)
    {
        aint[nod] = sp[st];
        wh[nod] = st;
        return;
    }
    int mid = (st + dr) / 2;
    build(nod << 1, st, mid);
    build(nod << 1|1, mid+1, dr);
    if(aint[nod << 1] <= aint[nod << 1|1])
    {
        aint[nod] = aint[nod << 1];
        wh[nod] = wh[nod << 1];
    }
    else
    {
        aint[nod] = aint[nod << 1|1];
        wh[nod] = wh[nod << 1|1];
    }
}

void build2(int nod, int st, int dr)
{
    if(st == dr)
    {
        aint2[nod] = sp2[st];
        wh2[nod] = st;
        return;
    }
    int mid = (st + dr) / 2;
    build2(nod << 1, st, mid);
    build2(nod << 1|1, mid+1, dr);
    if(aint2[nod << 1] < aint2[nod << 1|1])
    {
        aint2[nod] = aint2[nod << 1];
        wh2[nod] = wh2[nod << 1];
    }
    else
    {
        aint2[nod] = aint2[nod << 1|1];
        wh2[nod] = wh2[nod << 1|1];
    }
}

pair<int, int> query(int nod, int st, int dr, int L, int R)
{
    if(dr < L || st > R)
        return {100000001, 100000001};
    if(L <= st && dr <= R)
        return {aint[nod], wh[nod]};
    int mid = (st + dr) / 2;
    pair<int, int> xst = query(nod << 1, st, mid, L, R);
    pair<int, int> xdr = query(nod << 1|1, mid+1, dr, L, R);
    if(xst.fi <= xdr.fi)
        return xst;
    return xdr;
}

pair<int, int> query2(int nod, int st, int dr, int L, int R)
{
    if(dr < L || st > R)
        return {100000001, 100000001};
    if(L <= st && dr <= R)
        return {aint2[nod], wh2[nod]};
    int mid = (st + dr) / 2;
    pair<int, int> xst = query2(nod << 1, st, mid, L, R);
    pair<int, int> xdr = query2(nod << 1|1, mid+1, dr, L, R);
    if(xst.fi < xdr.fi)
        return xst;
    return xdr;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n;
    cin >> s;
    s = ' ' + s;
    for(int i = 1; i <= n; ++i)
        sp[i] = sp[i-1] + (s[i] == 'C' ? 1 : -1);
    for(int i = n; i >= 1; --i)
        sp2[i] = sp2[i+1] + (s[i] == 'C' ? 1 : -1);
    for(int i = n; i >= 1; --i)
        if(s[i] == 'T')
        {
            if(i+1 > n || s[i+1] == 'C')
                lstT[i] = i;
            else
                lstT[i] = lstT[i+1];
        }
    for(int i = 1; i <= n; ++i)
        if(s[i] == 'T')
        {
            if(i == 1 || s[i-1] == 'C')
                lstDT[i] = i;
            else
                lstDT[i] = lstDT[i-1];
        }
    for(int i = 1; i <= n; ++i)
        sT[i] = sT[i-1] + (s[i] == 'T');
    build(1, 1, n);
    build2(1, 1, n);
    cin >> q;
    for(; q; --q)
    {
        int st, dr;
        cin >> st >> dr;
        if(sT[dr] - sT[st-1] == dr - st + 1)
        {
            cout << dr - st + 1 << '\n';
            continue;
        }
        int ans = 0;
        if(s[st] == 'T')
        {
            ans += lstT[st] - st + 1;
            st = lstT[st] + 1;
        }
        if(s[dr] == 'T')
        {
            ans += dr - lstDT[dr] + 1;
            dr = lstDT[dr] - 1;
        }
        pair<int, int> bst = query(1, 1, n, st, dr);
        pair<int, int> bst2 = query2(1, 1, n, st, dr);
        int val1 = 0, val2 = 0;
        // left side
        if(sp[st - 1] - bst.fi <= 0);
        else
        {
            pair<int, int> bst3 = query(1, 1, n, st, lstDT[bst.se] - 1);
            ans += max(0, sp[st - 1] - bst3.fi);
            val1 = bst.fi + max(0, sp[st - 1] - bst3.fi);
        }
        if(sp2[dr + 1] - bst2.fi <= 0);
        else
        {
            pair<int, int> bst4 = query2(1, 1, n, lstT[bst2.se] + 1, dr);
            ans += max(0, sp2[dr + 1] - bst4.fi);
            val2 = bst2.fi + max(0, sp2[dr + 1] - bst4.fi);
        }
        ans -= min(val1, val2);
        cout << ans << '\n';
    }
    return 0;
}

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18