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Submission #725761

# Submission time Handle Problem Language Result Execution time Memory
725761 2023-04-18T02:49:15 Z josanneo22 Alternating Heights (CCO22_day1problem1) C++17
17 / 25
 1000 ms 74796 KB 
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int rd() {
    int x = 0, w = 1;
    char ch = getchar();
    for (; ch > '9' || ch < '0'; ch = getchar()) if (ch == '-') w = -1;
    for (; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
    return x * w;
}
const int maxn = 3e3 + 4;
int n;
vector<int> adj[maxn];
vector<char> color;
vector<int> parent;
int cycle_start, cycle_end;

bool dfs(int v) {
    color[v] = 1;
    for (int u : adj[v]) {
        if (color[u] == 0) {
            parent[u] = v;
            if (dfs(u))
                return true;
        }
        else if (color[u] == 1) {
            cycle_end = v;
            cycle_start = u;
            return true;
        }
    }
    color[v] = 2;
    return false;
}

vector<int> find_cycle() {
    color.assign(n, 0);
    parent.assign(n, -1);
    cycle_start = -1;
    for (int v = 0; v < n; v++) {
        if (color[v] == 0 && dfs(v))
            break;
    }
    if (cycle_start == -1) {
        return { -1 };
    }
    else {
        vector<int> cycle;
        cycle.push_back(cycle_start);
        for (int v = cycle_end; v != cycle_start; v = parent[v])
            cycle.push_back(v);
        cycle.push_back(cycle_start);
        reverse(cycle.begin(), cycle.end());
        return cycle;
    }
}
void solve() {
    int k, q; cin >> n >> k >> q;
    vector<int> a(n);
    for (auto& x : a) cin >> x;
    if (k == 2) {
        int ok[n + 1][n + 1];
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                ok[i][j] = 0;
            }
        }
        for (int i = 0; i < n; i++) {
            ok[i][i] = 1;
            for (int j = i + 1; j < n; j++) {
                if (a[j] != a[j - 1]) ok[i][j] |= ok[i][j - 1];
                else {
                    ok[i][j] = 0; break;
                }
            }
        }
        for (int queries = 0; queries < q; queries++) {
            int l, r; cin >> l >> r;
            l--; r--;
            if (ok[l][r]) cout << "YES\n";
            else cout << "NO\n";
        }
    }
    else if (n <= 500 && k <= 5) {
        int ok[n + 5][n + 5];
        for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) ok[i][j] = 0;
        for (int f = 0; f < n; f++) {
            for (int s = f + 1; s < n; s++) {
                for (int i = 0; i < n; i++) adj[i].clear();
                int cnt = 0;
                int l = f, r = s;
                for (int i = l; i <= r; i++) {
                    if (cnt % 2 == 1) {
                        if (i - 1 >= l)adj[a[i - 1]].push_back(a[i]);
                        if (i + 1 <= r) adj[a[i + 1]].push_back(a[i]);
                    }
                    else {
                        if (i + 1 <= r) adj[a[i]].push_back(a[i + 1]);
                        if (i - 1 >= l) adj[a[i]].push_back(a[i - 1]);
                    }
                    cnt++;
                }
                vector<int> meow = find_cycle();
                int yeaaaa = (meow[0] == -1);
                if (yeaaaa)ok[l][r] = 1;
            }
        }
        for (int queries = 0; queries < q; queries++) {
            int l, r; cin >> l >> r;
            l--; r--;
            if (ok[l][r]) cout << "YES\n";
            else cout << "NO\n";
        }
    }
    else {
        for (int queries = 0; queries < q; queries++) {
            int l, r; cin >> l >> r;
            l--; r--;
            for (int i = 0; i < n; i++) adj[i].clear();
            int cnt = 0;
            for (int i = l; i <= r; i++) {
                if (cnt % 2 == 1) {
                    if (i - 1 >= l)adj[a[i - 1]].push_back(a[i]);
                    if (i + 1 <= r) adj[a[i + 1]].push_back(a[i]);
                }
                else {
                    if (i + 1 <= r) adj[a[i]].push_back(a[i + 1]);
                    if (i - 1 >= l) adj[a[i]].push_back(a[i - 1]);
                }
                cnt++;
            }
            vector<int> meow = find_cycle();
            int yeaaaa = (meow[0] == -1);
            if (yeaaaa) cout << "YES\n";
            else cout << "NO\n";
        }
    }
}
signed main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    int tt = 1; //cin>>tt;
    while (tt--) {
        solve();
    }
}

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 269 ms 73924 KB Output is correct
2 Correct 275 ms 73932 KB Output is correct
3 Correct 266 ms 73708 KB Output is correct
4 Correct 124 ms 3344 KB Output is correct
5 Correct 128 ms 3484 KB Output is correct
6 Correct 265 ms 73560 KB Output is correct
7 Correct 276 ms 73420 KB Output is correct
8 Correct 279 ms 73804 KB Output is correct
9 Correct 273 ms 73736 KB Output is correct
10 Correct 296 ms 73932 KB Output is correct
11 Correct 286 ms 74536 KB Output is correct
12 Correct 266 ms 74796 KB Output is correct

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 513 ms 5476 KB Output is correct
2 Correct 523 ms 13080 KB Output is correct
3 Correct 155 ms 12908 KB Output is correct
4 Correct 113 ms 8240 KB Output is correct
5 Correct 143 ms 9500 KB Output is correct
6 Correct 521 ms 12904 KB Output is correct
7 Correct 509 ms 12996 KB Output is correct
8 Correct 155 ms 13032 KB Output is correct
9 Correct 637 ms 13460 KB Output is correct
10 Correct 813 ms 13952 KB Output is correct
11 Correct 768 ms 13900 KB Output is correct
12 Correct 1 ms 340 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 54 ms 548 KB Output is correct
3 Correct 56 ms 552 KB Output is correct
4 Correct 37 ms 70788 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 3 ms 340 KB Output is correct
7 Correct 52 ms 468 KB Output is correct
8 Correct 64 ms 552 KB Output is correct
9 Correct 72 ms 560 KB Output is correct
10 Correct 79 ms 548 KB Output is correct
11 Correct 83 ms 552 KB Output is correct
12 Correct 76 ms 564 KB Output is correct

Subtask #4
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 269 ms 73924 KB Output is correct
2 Correct 275 ms 73932 KB Output is correct
3 Correct 266 ms 73708 KB Output is correct
4 Correct 124 ms 3344 KB Output is correct
5 Correct 128 ms 3484 KB Output is correct
6 Correct 265 ms 73560 KB Output is correct
7 Correct 276 ms 73420 KB Output is correct
8 Correct 279 ms 73804 KB Output is correct
9 Correct 273 ms 73736 KB Output is correct
10 Correct 296 ms 73932 KB Output is correct
11 Correct 286 ms 74536 KB Output is correct
12 Correct 266 ms 74796 KB Output is correct
13 Correct 513 ms 5476 KB Output is correct
14 Correct 523 ms 13080 KB Output is correct
15 Correct 155 ms 12908 KB Output is correct
16 Correct 113 ms 8240 KB Output is correct
17 Correct 143 ms 9500 KB Output is correct
18 Correct 521 ms 12904 KB Output is correct
19 Correct 509 ms 12996 KB Output is correct
20 Correct 155 ms 13032 KB Output is correct
21 Correct 637 ms 13460 KB Output is correct
22 Correct 813 ms 13952 KB Output is correct
23 Correct 768 ms 13900 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 0 ms 340 KB Output is correct
26 Correct 54 ms 548 KB Output is correct
27 Correct 56 ms 552 KB Output is correct
28 Correct 37 ms 70788 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 3 ms 340 KB Output is correct
31 Correct 52 ms 468 KB Output is correct
32 Correct 64 ms 552 KB Output is correct
33 Correct 72 ms 560 KB Output is correct
34 Correct 79 ms 548 KB Output is correct
35 Correct 83 ms 552 KB Output is correct
36 Correct 76 ms 564 KB Output is correct
37 Execution timed out 1065 ms 1320 KB Time limit exceeded
38 Halted 0 ms 0 KB -