oj.uz

Submission #1100589

# Submission time Handle Problem Language Result Execution time Memory
1100589 2024-10-14T09:31:31 Z crafticat Sprinklers (CEOI24_sprinklers) C++17
6 / 100
 827 ms 12084 KB 
#include <bits/stdc++.h>

using namespace std;
template<typename T>
using V = vector<T>;
using vi = V<int>;
using vb = V<bool>;
using pi = pair<int,int>;


vi water, flowers;
V<bool> types;
set<int> problems;
constexpr int inf = 1e9 + 7;

bool between(int l, int r) {
    auto it = problems.upper_bound(l);
    if (it == problems.end() || *it >= r) return true;
    return false;
}

int pos(V<V<int>> &dp, int i, int lastR, int r) {
    int leftR = -1;
    if (i >= 0) {
        for (int j = 0; j < 3; ++j) {
            if (j == 0) leftR = water[i];
            if (j == 1 && i - 1 >= 0) leftR = water[i - 1] + r;
            if (j == 2) leftR = water[i] + r;
            if (dp[i][j] == -1) continue;
            if (between(leftR, lastR)) return j;
        }
    } else {
       return between(0, lastR) ? 0 : -1;
    }
    return -1;
}

bool ok(int r) {
    V<V<int>> dp(water.size() + 1, vi(3,-1));

    for (int i = 0; i < water.size(); ++i) {
        for (int j = 0; j < 3; ++j) {
            int lastR = -1;
            if (j == 0) lastR = water[i] - r;
            if (j == 1 && between(water[i - 1] + r, water[i] - r)) lastR = water[i] - r;
            if (j == 2) lastR = water[i];
            dp[i][j] = pos(dp,i - 1 + (j == 1 ? -1 : 0),lastR, r);
        }
    }

    // Backtrace
    int last = dp[water.size() - 1][2];
    int i = water.size() - 1;
    if (last == -1) return false;
    while (last != -1) {
        if (last == 1) {
            types.push_back(false);
            types.push_back(true);
            if (i - 2 < 0) return true;
            last = dp[i - 2][last];
            i -= 2;
        } else {
            types.push_back(last == 2);
            if (i - 1 < 0) return true;
            last = dp[i - 1][last];
            i--;
        }
    }
    return true;
}

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

    int n, m; cin >> n >> m;
    water.resize(n + 1);
    flowers.resize(m);

    for (int i = 0; i < n; ++i) {
        cin >> water[i];
        water[i]++;
    }
    water[n] = inf;
    for (int i = 0; i < m; ++i) {
        cin >> flowers[i];
        flowers[i]++;
        problems.insert(flowers[i]);
    }

    int l = 0, r = inf; // Last true
    while (r > l) {
        int mid = l + (r - l) / 2;
        if (ok(mid)) {
            r = mid;
        } else
            l = mid + 1;
    }

    types.clear();
    ok(l);
    if (l == inf) {
        cout << -1;
        return 0;
    }
    //if (l == 0) l++;
    cout << l << "\n";
    types.pop_back();
    std::reverse(types.begin(), types.end());
    for (auto x : types) {
        cout << (x ? "R" : "L");
    }
    return 0;
}

Compilation message

Main.cpp: In function 'bool ok(int)':
Main.cpp:41:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     for (int i = 0; i < water.size(); ++i) {
      |                     ~~^~~~~~~~~~~~~~

Subtask #0
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Correct
2 Correct 1 ms 336 KB Correct

Subtask #1
0.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Correct
2 Incorrect 20 ms 3664 KB User solution is incorrect
3 Halted 0 ms 0 KB -

Subtask #2
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Correct
2 Correct 33 ms 3920 KB Correct
3 Correct 39 ms 1304 KB Correct
4 Correct 626 ms 12084 KB Correct
5 Correct 600 ms 12060 KB Correct
6 Correct 1 ms 336 KB Correct
7 Correct 1 ms 336 KB Correct
8 Correct 464 ms 8300 KB Correct
9 Correct 495 ms 8752 KB Correct
10 Correct 814 ms 10840 KB Correct
11 Correct 201 ms 7200 KB Correct
12 Correct 261 ms 7380 KB Correct
13 Correct 695 ms 9960 KB Correct
14 Correct 662 ms 10524 KB Correct
15 Correct 627 ms 10528 KB Correct
16 Correct 637 ms 9260 KB Correct

Subtask #3
0.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Correct
2 Correct 1 ms 336 KB Correct
3 Correct 1 ms 336 KB Correct
4 Correct 1 ms 336 KB Correct
5 Correct 1 ms 336 KB Correct
6 Incorrect 1 ms 336 KB User solution is incorrect
7 Halted 0 ms 0 KB -

Subtask #4
0.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Correct
2 Correct 131 ms 4392 KB Correct
3 Incorrect 827 ms 11532 KB Incorrect string length
4 Halted 0 ms 0 KB -

Subtask #5
0.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Correct
2 Correct 1 ms 336 KB Correct
3 Incorrect 20 ms 3664 KB User solution is incorrect
4 Halted 0 ms 0 KB -