Submission #209333

#	Time	Username	Problem	Language	Result	Execution time	Memory
209333		papa	Grudanje (COCI19_grudanje)	C++14	70 / 70	312 ms	13996 KiB

grudanje

#include <bits/stdc++.h>

using namespace std;

int n;
int q;
int pref[30][100005];
string s;
vector<pair<int,int> > pa;
int p[100005];

//koriste se prefiksne sume da
//bi za svaki karakter proverilo
//koliko se puta pojavljuje u intervalu l,r
//i zatim se radi binarna po resenju jer ako je neki
//broj od n karaktera dobar posle x grudvi bice dobar i posle x+1

bool check(int x)
{
    string z = s;
    for(int i=1;i<=x;i++) z[p[i]] = '*';

    for(int i=0;i<n;i++)
    {
        if(z[i]=='*')
        {
            for(int j =0;j<26;j++)
                pref[j][i] = (i-1>=0) ? pref[j][i-1] : 0;
            continue;
        }
        int ind = z[i] - 'a';
        for(int j = 0;j<26;j++)
        {
            if(j==ind)
            {
                if(i==0) pref[j][i] = 1;
                else pref[j][i] = pref[j][i-1] + 1;
            }
            else
            {
                if(i==0) pref[j][i] = 0;
                else pref[j][i] = pref[j][i-1];
            }
        }
    }

    for(auto v : pa)
    {
        int l = v.first;
        int r = v.second;
        for(int i=0;i<26;i++)
        {
            int x;
            if(l==0) x = pref[i][r];
            else x = pref[i][r] - pref[i][l-1];
            if(x > 1)
            {
                //cout << "lose" << "\n";
                //cout << pref[i][r] << " " << pref[i][l-1] << "\n";
                //cout << x << "\n";
                //cout << l << " " << r << "\n";
                return false;
            }
        }
    }

    return true;
}

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

    cin >> s;
    n=s.size();
    cin >> q;

    for(int i=1;i<=q;i++)
    {
        int l,r;
        cin >> l >> r;
        pa.push_back({l-1,r-1});
    }

    for(int i=1;i<=n;i++)
    {
        cin >> p[i];
        p[i]--;
    }

    int lo = 0;
    int hi = n;
    int res = -1;

    for(int i=1;i<=30;i++)
    {
        int mid = (lo+hi)/2;
        //cout << mid << "\n";
        if(check(mid))
        {
            res = mid;
            hi = mid-1;
        }
        else lo = mid+1;
    }

    cout << res;

    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 7 / 7
• Subtask 5: 7 / 7
• Subtask 6: 7 / 7
• Subtask 7: 7 / 7
• Subtask 8: 7 / 7
• Subtask 9: 7 / 7
• Subtask 10: 7 / 7