oj.uz

답안 #640957

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
640957 2022-09-15T15:24:02 Z piOOE Shortcut (IOI16_shortcut) C++17
0 / 100
 2000 ms 340 KB 
#pragma GCC optimize("O3,unroll-loops")

#include <bits/stdc++.h>
#include "shortcut.h"

using namespace std;
using ll = long long;

constexpr int N = 3001;

int cant[N][N], mx_pref[N][N], mx_suf[N][N];
int sz[N], nxt[N][N];

ll pref[N];

ll dist(int i, int j) {
    if (i > j) swap(i, j);
    return pref[j] - pref[i];
}

ll find_shortcut(int n, vector<int> l, vector<int> d, int c) {
    pref[0] = 0;
    for (int i = 0; i < n - 1; ++i) {
        pref[i + 1] = pref[i] + l[i];
    }

    ll high = 0;
    for (int i = 0; i < n; ++i) {
        for (int j = i + 1; j < n; ++j) {
            high = max(high, dist(i, j) + d[i] + d[j]);
        }
    }

    ll low = 0;
    while (low + 1 < high) {
        ll mid = (low + high) >> 1;
        auto check = [&]() -> bool {
            vector<int> prefix;
            for (int i = 0; i < n; ++i) {
                sz[i] = 0;
                for (int j = 0; j < n; ++j) {
                    if (i != j && dist(i, j) + d[i] + d[j] > mid) {
                        cant[i][sz[i]++] = j;
                    }
                }
                if (sz[i]) {
                    if (cant[i][0] < i && cant[i][sz[i] - 1] > i) {
                        return false;
                    }
                    if (cant[i][0] > i) {
                        fill(nxt[i], nxt[i] + n + 1, sz[i]);
                        for (int j = 0; j < sz[i]; ++j) {
                            nxt[i][cant[i][j]] = j;
                        }
                        for (int j = n - 1; j > -1; --j) {
                            if (nxt[i][j] == sz[i]) {
                                nxt[i][j] = nxt[i][j + 1];
                            }
                        }
                        prefix.push_back(i);
                        for (int j = 0; j < sz[i]; ++j) {
                            if (j == 0 || d[cant[i][j]] > dist(cant[i][j], mx_pref[i][j - 1]) + d[mx_pref[i][j - 1]]) {
                                mx_pref[i][j] = cant[i][j];
                            } else {
                                mx_pref[i][j] = mx_pref[i][j - 1];
                            }
                        }
                        for (int j = sz[i] - 1; j > -1; --j) {
                            if (j == sz[i] - 1 ||
                                d[cant[i][j]] > dist(cant[i][j], mx_suf[i][j + 1]) + d[mx_suf[i][j + 1]]) {
                                mx_suf[i][j] = cant[i][j];
                            } else {
                                mx_suf[i][j] = mx_suf[i][j + 1];
                            }
                        }
                    }
                }
            }
            for (int p = 0; p < n; ++p) {
                int L = 0, R = n;
                for (int i: prefix) {
                    ll D = dist(p, i) + d[i];
                    mid -= D + c;
                    int l = -1, r = cant[i][sz[i] - 1];
                    while (l + 1 < r) {
                        int m = (l + r) >> 1;
                        auto it = nxt[i][m];
                        if (dist(m, mx_suf[i][it]) + d[mx_suf[i][it]] <= mid) {
                            r = m;
                        } else {
                            l = m;
                        }
                    }
                    L = max(L, r);
                    if (L >= R) {
                        return false;
                    }
                    l = cant[i][0] - 1, r = n;
                    while (l + 1 < r) {
                        int m = (l + r) >> 1;
                        auto it = nxt[i][m + 1];
                        if (it == 0 || dist(m, mx_pref[i][it - 1]) + d[mx_pref[i][it - 1]] <= mid) {
                            l = m;
                        } else {
                            r = m;
                        }
                    }
                    R = min(R, r);
                    mid += D + c;
                    if (L >= R) {
                        break;
                    }
                }
                if (L < R) {
                    return true;
                }
            }
            return false;
        };
        if (check()) {
            high = mid;
        } else {
            low = mid;
        }
    }
    return high;
}

Subtask #1
0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
0 / 14.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #3
0 / 8.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #4
0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #5
0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #7
0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #8
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB n = 4, 80 is a correct answer
2 Execution timed out 2077 ms 340 KB Time limit exceeded
3 Halted 0 ms 0 KB -