CSES - Putka Open 2020 – 4/5 - Results
Submission details
Task:Ruudukko
Sender:Mahtimursu
Submission time:2023-03-16 23:56:49 +0200
Language:C++17
Status:READY
Result:100
Feedback
groupverdictscore
#1ACCEPTED5
#2ACCEPTED12
#3ACCEPTED27
#4ACCEPTED28
#5ACCEPTED28
Test results
testverdicttimegroup
#1ACCEPTED0.00 s1, 5details
#2ACCEPTED0.01 s2, 5details
#3ACCEPTED0.01 s3, 5details
#4ACCEPTED0.01 s4, 5details
#5ACCEPTED0.02 s5details
#6ACCEPTED0.01 s5details
#7ACCEPTED0.00 s2, 5details
#8ACCEPTED0.00 s2, 5details
#9ACCEPTED0.00 s3, 5details
#10ACCEPTED0.00 s3, 5details
#11ACCEPTED0.01 s3, 5details
#12ACCEPTED0.00 s3, 5details
#13ACCEPTED0.01 s4, 5details
#14ACCEPTED0.03 s5details
#15ACCEPTED0.02 s3, 5details
#16ACCEPTED0.06 s5details

Code

#include <bits/stdc++.h>

typedef long long ll;

#define M 1000000007
#define N (1 << 18)

#define y first
#define x second

using namespace std;

map<tuple<int, int, pair<int, int>, pair<int, int>>, int> dp;

bool check_small(int h, int w, int y0, int x0, int y1, int x1) {
	if (x0 > x1 || (x0 == x1 && y0 > y1)) return check_small(h, w, y1, x1, y0, x0);
 
	if (h == 1) {
		if (x0 == 0 && x1 == w-1) return true;
		if (x0 == w-1 && x1 == 0) return true;
		return false;
	} else {
		if (x0 == x1 && 0 < x0 && x0 < w-1) return false;
		return true;
	}
}

bool works(int h, int w, int y0, int x0, int y1, int x1) {
	if (y0 == y1 && x0 == x1) return false;
	if (w < h) return works(w, h, x0, y0, x1, y1);
	if (! ((h*w ^ abs(x0 - x1) ^ abs(y0 - y1)) & 1)) return false;
	if ((h*w & 1) && ((x0 + y0) & 1)) return false;
 
	if (h <= 2) return check_small(h, w, y0, x0, y1, x1);
	if (h == 3 && (!(w & 1))) {
		if (y0 == 1) {
			if ((x0 & 1) && x1 < x0) return false;
			if (!(x0 & 1) && x1 > x0) return false;
		} else {
			if (!(x0 & 1) && (x1 < x0 - 1)) return false;
			if ((x0 & 1) && (x1 > x0 + 1)) return false;
		}
	}   
	return true;
}

bool inside(int n, int m, pair<int, int> p) {
    return p.x <= m && p.y <= n && p.x > 0 && p.y > 0;
}

bool ok(int h, int w, pair<int, int> s, pair<int, int> t) {
    return works(h, w, s.y - 1, s.x - 1, t.y - 1, t.x - 1);
}

pair<int, int> offset(pair<int, int> p, pair<int, int> off) {
    return {p.y + off.y, p.x + off.x};
}

map<tuple<int, int, pair<int, int>, pair<int, int>>, pair<tuple<int, int, pair<int, int>, pair<int, int>>, tuple<int, int, pair<int, int>, pair<int, int>>>> mp;
map<tuple<int, int, pair<int, int>, pair<int, int>>, string> connector;

const int cutoff = 20;

int solve(int n, int m, pair<int, int> s, pair<int, int> t) {
    if (s > t) return solve(n, m, t, s);
    int best = n * m;
    if (best <= cutoff) return best;
    //if (dp[make_tuple(n, m, s, t)]) return dp[make_tuple(n, m, s, t)];

    int min_i = min(s.y, t.y);
    int max_i = max(s.y, t.y);

    int min_j = min(s.x, t.x);
    int max_j = max(s.x, t.x);

    if (min_i > 2) {
        if (ok(n - 2, m, offset(s, {-2, 0}), offset(t, {-2, 0}))) {
            auto x1 = make_tuple(2, m, make_pair(1, 0), make_pair(1,0));
            auto x2 = make_tuple(n - 2, m, offset(s, {-2, 0}), offset(t, {-2, 0}));
            mp[make_tuple(n, m, s, t)] = make_pair(x1, x2);

            return dp[make_tuple(n, m, s, t)] = solve(n - 2, m, offset(s, {-2, 0}), offset(t, {-2, 0}));
        }
    }

    if (max_i < n - 1) {
        if (ok(n - 2, m, s, t)) {
            auto x1 = make_tuple(2, m, make_pair(n - 2, 0), make_pair(2,0));
            auto x2 = make_tuple(n - 2, m, s, t);
            mp[make_tuple(n, m, s, t)] = make_pair(x1, x2);

            return dp[make_tuple(n, m, s, t)] = solve(n - 2, m, s, t);
        }
    }

    if (min_j > 2) {
        if (ok(n, m - 2, offset(s, {0, -2}), offset(t, {0, -2}))) {
            auto x1 = make_tuple(n, 2, make_pair(0, 1), make_pair(0,1));
            auto x2 = make_tuple(n, m - 2, offset(s, {0, -2}), offset(t, {0, -2}));
            mp[make_tuple(n, m, s, t)] = make_pair(x1, x2);

            return dp[make_tuple(n, m, s, t)] = solve(n, m - 2, offset(s, {0, -2}), offset(t, {0, -2}));
        }
    }

    if (max_j < m - 1) {
        if (ok(n, m - 2, s, t)) {
            auto x1 = make_tuple(n, 2, make_pair(0, m - 2), make_pair(0,2));
            auto x2 = make_tuple(n, m - 2, s, t);
            mp[make_tuple(n, m, s, t)] = make_pair(x1, x2);

            return dp[make_tuple(n, m, s, t)] = solve(n, m - 2, s, t);
        }
    }

    pair<tuple<int, int, pair<int, int>, pair<int, int>>, tuple<int, int, pair<int, int>, pair<int, int>>> ans;
    string conn;
    
    if (n >= m) {
        set<int> st_j;
        st_j.insert(1);
        st_j.insert(2);
        
        if (m % 2 == 0) st_j.insert(m);
        else st_j.insert(m - 1);
        for (int j : st_j) {
            int first_n = 2;
            int second_n = n - 2;

            pair<int, int> first_e = {first_n, j};
            pair<int, int> second_e = {first_n + 1, j};

            if (inside(first_n, m, s) 
                && inside(second_n, m, offset(t, {-first_n, 0}))
                && ok(first_n, m, s, first_e) 
                && ok(second_n, m, offset(t, {-first_n, 0}), offset(second_e, {-first_n, 0}))
            ) {
                solve(first_n, m, s, first_e);
                solve(second_n, m, offset(t, {-first_n, 0}), offset(second_e, {-first_n, 0})); 

                auto x1 = make_tuple(first_n, m, s, first_e);
                auto x2 = make_tuple(second_n, m, offset(second_e, {-first_n, 0}), offset(t, {-first_n, 0}));

                conn = "D";
                ans = make_pair(x1, x2);
                break;
            }

            /*if (inside(first_n, m, t) 
                && inside(second_n, m, offset(s, {-first_n, 0}))
                && ok(first_n, m, t, first_e) 
                && ok(second_n, m, offset(s, {-first_n, 0}), offset(second_e, {-first_n, 0}))
            ) {
                solve(first_n, m, t, first_e);
                solve(second_n, m, offset(s, {-first_n, 0}), offset(second_e, {-first_n, 0}));

                auto x1 = make_tuple(second_n, m, offset(s, {-first_n, 0}), offset(second_e, {-first_n, 0}));
                auto x2 = make_tuple(first_n, m, first_e, t);

                conn = "U";
                ans = make_pair(x1, x2);
                break;
            }*/
        }
    }
    
    if (m > n) {
        set<int> st_i;
        st_i.insert(1);
        st_i.insert(2);
        
        if (n % 2 == 0) st_i.insert(n);
        else st_i.insert(n - 1);
        for (int i : st_i) {
            int first_m = 2;
            int second_m = m - 2;

            pair<int, int> first_e = {i, first_m};
            pair<int, int> second_e = {i, first_m + 1};

            if (inside(n, first_m, s) 
                && inside(n, second_m, offset(t, {0, -first_m}))
                && ok(n, first_m, s, first_e) 
                && ok(n, second_m, offset(t, {0, -first_m}), offset(second_e, {0, -first_m}))
            ) { 
                solve(n, first_m, s, first_e);
                solve(n, second_m, offset(t, {0, -first_m}), offset(second_e, {0, -first_m}));
                
                auto x1 = make_tuple(n, first_m, s, first_e);
                auto x2 = make_tuple(n, second_m, offset(second_e, {0, -first_m}), offset(t, {0, -first_m}));

                conn = "R";
                ans = make_pair(x1, x2);
                break;
            }

            if (inside(n, first_m, t) 
                && inside(n, second_m, offset(s, {0, -first_m}))
                && ok(n, first_m, t, first_e) 
                && ok(n, second_m, offset(s, {0, -first_m}), offset(second_e, {0, -first_m}))
            ) {
                solve(n, first_m, t, first_e);
                solve(n, second_m, offset(s, {0, -first_m}), offset(second_e, {0, -first_m}));
                    
                auto x1 = make_tuple(n, second_m, offset(s, {0, -first_m}), offset(second_e, {0, -first_m}));
                auto x2 = make_tuple(n, first_m, first_e, t);

                conn = "L";
                ans = make_pair(x1, x2);
                break;
            }
        }
    }
    
    //if (best == n * m) exit(-1);

    mp[make_tuple(n, m, s, t)] = ans;
    connector[make_tuple(n, m, s, t)] = conn;
    return 1;
    //return dp[make_tuple(n, m, s, t)] = best;
}

string rev(string s) {
    map<char, char> sw;
    sw['U'] = 'D';
    sw['D'] = 'U';
    sw['L'] = 'R';
    sw['R'] = 'L';

    string ans;
    for (char c : s) ans += sw[c];
    reverse(ans.begin(), ans.end());
    return ans;
}

bool vis[51][51];

string run_brute(int n, int m, pair<int, int> c, pair<int, int> t, int left) {
    if (c.x < 1 || c.x > m || c.y < 1 || c.y > n) return "X";
    if (vis[c.y][c.x]) return "X";
    if (left == 0) {
        return c == t ? "" : "X";
    }

    vis[c.y][c.x] = 1;

    string p = run_brute(n, m, {c.y - 1, c.x}, t, left - 1);
    if (p != "X") return "U" + p;

    p = run_brute(n, m, {c.y + 1, c.x}, t, left - 1);
    if (p != "X") return "D" + p;

    p = run_brute(n, m, {c.y, c.x - 1}, t, left - 1);
    if (p != "X") return "L" + p;

    p = run_brute(n, m, {c.y, c.x + 1}, t, left - 1);
    if (p != "X") return "R" + p;

    vis[c.y][c.x] = 0;
    return "X";
}

string brute(int n, int m, pair<int, int> s, pair<int, int> t) {
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) vis[i][j] = 0;
    }

    return run_brute(n, m, s, t, n * m - 1);
}

string c2(int n, int m, pair<int, int> s, pair<int, int> t) {
    pair<int, int> dif = {s.y - t.y, s.x - t.x};

    string ans;

    if (dif == make_pair(0, -1)) {
        ans += string(s.x - 1, 'L');
        ans += s.y == 2 ? "U" : "D";
        ans += string(m - 1, 'R');
        ans += s.y == 2 ? "D" : "U";
        ans += string(m - t.x, 'L');
    }
    if (dif == make_pair(0, 1)) {
        ans += string(m - s.x, 'R');
        ans += s.y == 2 ? "U" : "D";
        ans += string(m - 1, 'L');
        ans += s.y == 2 ? "D" : "U";
        ans += string(t.x - 1, 'R');
    }
    if (dif == make_pair(-1, 0)) {
        ans += string(s.y - 1, 'U');
        ans += s.x == 2 ? "L" : "R";
        ans += string(n - 1, 'D');
        ans += s.x == 2 ? "R" : "L";
        ans += string(n - t.y, 'U');
    }
    if (dif == make_pair(1, 0)) {
        ans += string(n - s.y, 'D');
        ans += s.x == 2 ? "L" : "R";
        ans += string(n - 1, 'U');
        ans += s.x == 2 ? "R" : "L";
        ans += string(t.y - 1, 'D');
    }

    return ans;
}

string parse_result(int n, int m, pair<int, int> s, pair<int, int> t) {
    if (s > t) return rev(parse_result(n, m, t, s));
    
    int best = n * m;
    if (best <= cutoff) return brute(n, m, s, t);

    auto p1 = mp[make_tuple(n, m, s, t)].first;
    auto p2 = mp[make_tuple(n, m, s, t)].second;

    map<char, pair<int, int>> dir_to_dif;
    dir_to_dif['U'] = {-1, 0};
    dir_to_dif['D'] = {1, 0};
    dir_to_dif['R'] = {0, 1};
    dir_to_dif['L'] = {0, -1};

    if (get<3>(p1).y == 0 || get<3>(p1).x == 0) {
        string path = parse_result(get<0>(p2), get<1>(p2), get<2>(p2), get<3>(p2));

        string res;

        pair<int, int> tgt = get<2>(p1);
        pair<int, int> pos = get<2>(p2);

        if (pos.x == tgt.x || pos.y == tgt.y) {
            bool begin = 0;
            if (get<3>(p1).y == 1 && path[0] == 'D') {
                begin = 1;
            } else if (get<3>(p1).y > 1 && path[0] == 'U') {
                begin = 1;
            } else if (get<3>(p1).x == 1 && path[0] == 'R') {
                begin = 1;
            } else if (get<3>(p1).x > 1 && path[0] == 'L') {
                begin = 1;
            }

            if (begin) {
                pair<int, int> dif = dir_to_dif[path[res.size()]];
                pos = make_pair(pos.y + dif.y, pos.x + dif.x);
                res += (path[res.size()]);
            }
        }

        while (pos.x != tgt.x && pos.y != tgt.y) {
            pair<int, int> dif = dir_to_dif[path[res.size()]];
            pos = make_pair(pos.y + dif.y, pos.x + dif.x);
            res += (path[res.size()]);
        }

        string end_path = path.size() > res.size() + 1 ? path.substr(res.size() + 1, 1e5) : "";

        if (get<3>(p1).y == 1) {
            res = res + "U" + c2(2, get<1>(p1), {2, pos.x}, {2, pos.x + dir_to_dif[path[res.size()]].x}) + "D";
        } else if (get<3>(p1).y > 1) {
            res = res + "D" + c2(2, get<1>(p1), {1, pos.x}, {1, pos.x + dir_to_dif[path[res.size()]].x}) + "U";
        } else if (get<3>(p1).x == 1) {
            res = res + "L" + c2(get<0>(p1), 2, {pos.y, 2}, {pos.y + dir_to_dif[path[res.size()]].y, 2}) + "R";
        } else if (get<3>(p1).x > 1) {
            res = res + "R" + c2(get<0>(p1), 2, {pos.y, 1}, {pos.y + dir_to_dif[path[res.size()]].y, 1}) + "L";
        }

        return res + end_path;
    }

    string s1 = parse_result(get<0>(p1), get<1>(p1), get<2>(p1), get<3>(p1));
    string s2 = parse_result(get<0>(p2), get<1>(p2), get<2>(p2), get<3>(p2));

    return s1 + connector[make_tuple(n, m, s, t)] + s2;
}

void test_case() {
    int n, m;
    int sy, sx;
    int ty, tx;

    cin >> n >> m >> sy >> sx >> ty >> tx;

    if (!ok(n, m, {sy, sx}, {ty, tx})) {
        cout << "NO" << endl;
        return;
    }

    cout << "YES\n";
    //cout << n << " " << m << " " << sy << " " << sx << " " << ty << " " << tx << endl;
    solve(n, m, {sy, sx}, {ty, tx});
    string ans = parse_result(n, m, {sy, sx}, {ty, tx});
    cout << ans << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int t = 1;
    cin >> t;
    for (int i = 0; i < t; ++i) {
        test_case();
    }

    return 0;
}

Test details

Test 1

Group: 1, 5

Verdict: ACCEPTED

input
100
1 45 1 45 1 1
1 18 1 1 1 10
1 47 1 17 1 30
1 33 1 28 1 20
...

correct output
YES
LLLLLLLLLLLLLLLLLLLLLLLLLLLLLL...

user output
YES
LLLLLLLLLLLLLLLLLLLLLLLLLLLLLL...

Test 2

Group: 2, 5

Verdict: ACCEPTED

input
100
2 43 1 33 1 21
2 2 1 1 2 2
2 32 1 1 2 8
2 14 1 12 1 14
...

correct output
NO
NO
NO
NO
YES
...

user output
NO
NO
NO
NO
YES
...

Test 3

Group: 3, 5

Verdict: ACCEPTED

input
100
3 4 2 1 2 4
3 38 2 24 1 22
3 29 2 23 2 3
3 8 3 1 1 2
...

correct output
NO
NO
NO
YES
RRRRRRRUULDLULDLULDLLUR
...

user output
NO
NO
NO
YES
RRRRRURDRUULLLDLULDLLUR
...

Test 4

Group: 4, 5

Verdict: ACCEPTED

input
100
4 25 2 19 1 5
4 13 3 10 4 12
4 7 3 1 4 2
4 23 1 19 2 5
...

correct output
YES
DDRRRRRRULLLLLURRRRRULLLLLLLDD...

user output
YES
RRRRRRULLLLLLLDLULDLULDLULDLUL...

Test 5

Group: 5

Verdict: ACCEPTED

input
100
16 8 13 1 14 8
41 21 19 11 32 12
46 17 13 7 6 11
8 41 4 32 4 12
...

correct output
NO
YES
LURULURULURULURULURRDDDDDDDDDR...

user output
NO
YES
ULLLLLLLLLLUUUUUUUUUUUUUUUUURR...

Test 6

Group: 5

Verdict: ACCEPTED

input
100
31 38 18 35 31 37
35 48 7 13 21 21
46 21 25 2 4 19
35 2 13 2 35 1
...

correct output
YES
LLLLLLLLLLLLDRRRRRRRRRRRRDLLLL...

user output
YES
LDDDDDDDDDDDDDLLLLLLLLLLLLLLLL...

Test 7

Group: 2, 5

Verdict: ACCEPTED

input
100
2 4 1 3 1 4
2 4 2 2 1 1
2 4 2 3 1 2
2 4 2 3 1 4
...

correct output
YES
LLDRRRU
NO
NO
NO
...

user output
YES
LLDRRRU
NO
NO
NO
...

Test 8

Group: 2, 5

Verdict: ACCEPTED

input
100
2 5 1 2 2 4
2 5 1 2 1 1
2 5 2 1 1 2
2 5 1 1 1 5
...

correct output
YES
LDRRURRDL
YES
RRRDLLLLU
NO
...

user output
YES
LDRRURRDL
YES
RRRDLLLLU
NO
...

Test 9

Group: 3, 5

Verdict: ACCEPTED

input
100
3 4 1 1 2 3
3 4 2 4 3 2
3 4 2 1 3 1
3 4 1 4 3 4
...

correct output
YES
DDRRRUULLDR
NO
YES
URRRDDLULDL
...

user output
YES
DDRUURRDDLU
NO
YES
URDRURDDLLL
...

Test 10

Group: 3, 5

Verdict: ACCEPTED

input
100
3 5 3 4 3 2
3 5 3 5 2 3
3 5 3 1 2 2
3 5 3 1 3 2
...

correct output
NO
NO
YES
UURRRRDDLULDLU
NO
...

user output
NO
NO
YES
UURRRRDDLULDLU
NO
...

Test 11

Group: 3, 5

Verdict: ACCEPTED

input
100
3 8 2 8 1 2
3 8 2 4 1 7
3 8 3 4 2 7
3 8 2 5 3 1
...

correct output
NO
NO
NO
YES
LLLDRRRRURDRUULLLLLLLDD
...

user output
NO
NO
NO
YES
URRRDDLULDLLUULDDLUULDD
...

Test 12

Group: 3, 5

Verdict: ACCEPTED

input
100
3 9 1 3 2 9
3 9 1 6 1 5
3 9 3 6 2 8
3 9 3 2 3 4
...

correct output
NO
NO
NO
NO
NO
...

user output
NO
NO
NO
NO
NO
...

Test 13

Group: 4, 5

Verdict: ACCEPTED

input
100
4 4 2 2 1 4
4 4 4 1 2 2
4 4 2 1 4 3
4 4 3 1 3 3
...

correct output
YES
DDLUUURRDDDRUUU
YES
UUURRRDLDRDLLUU
NO
...

user output
YES
DDLUUURRDDDRUUU
YES
RRRUUULDDLLUURD
NO
...

Test 14

Group: 5

Verdict: ACCEPTED

input
100
12 27 6 22 1 8
6 25 3 2 4 4
6 16 4 6 5 2
36 33 8 6 1 6
...

correct output
YES
DLDDDDDRUUUURDDDDRUURDDRRULURU...

user output
YES
RULLDLULDLULDLULDLULDLUURRRRRR...

Test 15

Group: 3, 5

Verdict: ACCEPTED

input
100
3 12 3 5 1 4
3 20 3 19 2 19
3 34 3 9 2 9
3 38 2 15 3 15
...

correct output
YES
RRRRRRRUULDLULDLULDLULDLDLULDL...

user output
YES
RRRURDRURDRUULLLLLDLULDLDLULDL...

Test 16

Group: 5

Verdict: ACCEPTED

input
100
50 50 29 1 16 21
50 50 37 5 23 48
50 50 32 22 45 24
50 50 6 28 12 37
...

correct output
YES
DDDDDDDDDDDDDDDDDDDDDRUUUUUUUU...

user output
YES
DRUULURULURULURULURULURULURULU...