Submission #1239210

#	Time	Username	Problem	Language	Result	Execution time	Memory
1239210		faruk	Crossing (JOI21_crossing)	C++20	26 / 100	7092 ms	2920 KiB

Main

#include <bits/stdc++.h>
#define all(a) a.begin(), a.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

string cross(string &a, string &b)
{
    string c = "";
    for (int i = 0; i < a.size(); i++)
    {
        if (a[i] == b[i])
            c += a[i];
        else
            c += ('J' + 'O' + 'I' - a[i] - b[i]);
    }
    return c;
}

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

    set<string> strt = {"IO", "OO"};

    int n;
    cin >> n;
    vector<string> s(3);
    for (int i = 0; i < 3; i++)
        cin >> s[i];

    vector<bool> forced(n, true);
    for (int i = 0; i < n; i++)
    {
        if (s[0][i] != s[1][i] || s[0][i] != s[2][i] || s[1][i] != s[2][i])
            forced[i] = false;
    }

    vector<int> cmp(n);
    iota(all(cmp), 0);
    vector<vector<int>> per(4); 
    /*
    0, 1  and 2 are diff
    1, 0 and 2 are diff
    2, 0 and 1 are diff
    3 all are diff
    */
    for (int i = 0; i < n; i++)
    {
        if (forced[i])
            continue;
        set<char> s1;
        for (int k = 0; k < 3; k++)
            s1.insert(s[k][i]);
        if (s1.size() == 3)
            per[3].push_back(i);
        else {
            for (int j = 0; j < 3; j++)
            {
                bool ok = true;
                for (int k = 0; k < 3; k++)
                    if (j != k and s[j][i] == s[k][i])
                        ok = false;
                if (ok)
                    per[j].push_back(i);
            }
        }
    }

    int num_comps = 0;
    vector<vector<char>> variants(3, vector<char>(n));
    for (vector<int> ids : per)
    {
        if (!ids.empty())
            num_comps++;
        for (int i : ids)
        {
            variants[0][i] = s[0][i], variants[1][i] = s[1][i], variants[2][i] = s[2][i];
            for (int j = 0; j < 3; j++)
            {
                bool can_change = false;
                for (int k = 0; k < 3; k++)
                    if (j != k and variants[j][i] == variants[k][i])
                        can_change = true;
                if (!can_change)
                    continue;
                char me = 'J' + 'O' + 'I';
                for (int k = 0; k < 3; k++)
                    if (j != k)
                        me -= variants[k][i];
                variants[j][i] = me;
                break;
            }
        }
    }

    string t;
    int q;
    cin >> q;
    cin >> t;
    for (int Q = 0; Q <= q; Q++)
    {
        if (Q > 0)
        {
            int l, r;
            cin >> l >> r;
            char c;
            cin >> c;
            for (; l <= r; l++)
                t[l - 1] = c;
        }
        bool ok = true;
        for (vector<int> ids : per)
        {
            if (ids.empty())
                continue;
            int var = 0;
            for (int i = 0; i < 3; i++)
                if (t[ids[0]] == variants[i][ids[0]])
                    var = i;
            for (int i : ids)
                if (variants[var][i] != t[i])
                    ok = false;
        }
        for (int i = 0; i < n; i++)
            if (forced[i] and s[0][i] != t[i])
                ok = false;

        if (ok || num_comps > 4)
            cout << "Yes\n";
        else
            cout << "No\n";
    }
}

• Subtask 1: 3 / 3
• Subtask 2: 0 / 23
• Subtask 3: 23 / 23
• Subtask 4: 0 / 51