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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#227868#5532. KangarooCamillus100 ✓46ms70696kbC++203.7kb2023-10-28 01:24:282023-10-28 01:24:29

Judging History

你现在查看的是最新测评结果

  • [2023-10-28 01:24:29]
  • 评测
  • 测评结果:100
  • 用时:46ms
  • 内存:70696kb
  • [2023-10-28 01:24:28]
  • 提交

answer

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;

struct mint {
    static constexpr int mod = 1'000'000'007;
    int value = 0;

    mint() = default;
    mint(int value) : value(value) {}
};

mint operator+(const mint &A, const mint &B) {
    int value = A.value + B.value;
    if (value >= mint::mod) {
        value -= mint::mod;
    }
    return mint(value);
}

mint operator-(const mint &A, const mint &B) {
    int value = A.value + mint::mod - B.value;
    if (value >= mint::mod) {
        value -= mint::mod;
    }
    return mint(value);
}

mint operator*(const mint &A, const mint &B) {
    return mint(1ll * A.value * B.value % mint::mod);
}

mint recA(int l, int i, int j);
mint recB(int l, int i, int j);

struct saved {
    vector<vector<mint>> data0;
    vector<vector<bool>> mark0;
    vector<vector<mint>> data1;
    vector<vector<bool>> mark1;

    saved() {
        data0 = vector<vector<mint>>(2024, vector<mint>(2024));
        data1 = vector<vector<mint>>(2024, vector<mint>(2024));

        mark0 = vector<vector<bool>>(2024, vector<bool>(2024));
        mark1 = vector<vector<bool>>(2024, vector<bool>(2024));
    }

    bool contains(int l, int i, int j) const {
        if (i == 0) {
            return mark0[l][j];
        } else {
            return mark1[l][i];
        }
    };

    mint& get(int l, int i, int j) {
        if (i == 0) {
            mark0[l][j] = true;
            return data0[l][j];
        } else {
            mark1[l][i] = true;
            return data1[l][i];
        }
    }
};

saved savedA;
saved savedB;

mint recA(int l, int i, int j) {
    if (i > j) {
        if (l % 2 == 0) {
            return recB(l, j, i);
        } else {
            return recA(l, j, i);
        }
    }

    if (savedA.contains(l, i, j)) {
        return savedA.get(l, i, j);
    }
    
    if (l == 1) {
        if (i == 0 && j == 0) {
            return 1;
        } else {
            return 0;
        }
    }
    
    if (i == j) {
        return 0;
    }

    if (i == 0) {
        mint res = 0;
        if (l % 2 == 0) {
            if (j == 1) {
                for (int k = 0; k < j; k++) {
                    res = res + recA(l - 1, 0, k);
                }
            } else {
                res = recA(l, 0, j - 1) + recA(l - 1, 0, j - 1);
            }
        } else {
            if (j == 1) {
                for (int k = j; k <= l - 2; k++) {
                    res = res + recA(l - 1, 0, k);
                }
            } else {
                res = recA(l, 0, j - 1) - recA(l - 1, 0, j - 1);
            }
        }
        return savedA.get(l, i, j) = res;
    }

    return savedA.get(l, i, j) = recA(l, i - 1, j) - recB(l - 1, i - 1, j - 1);
}


mint recB(int l, int i, int j) {
    if (i > j) {
        if (l % 2 == 0) {
            return recA(l, j, i);
        } else {
            return recB(l, j, i);
        }
    }

    if (savedB.contains(l, i, j)) {
        return savedB.get(l, i, j);
    }

    if (l == 1) {
        if (i == 0 && j == 0) {
            return 1;
        } else {
            return 0;
        }
    }
    
    if (i == j) {
        return 0;
    }

    if (i == 0) {
        return savedB.get(l, i, j) = 0;
    }

    return savedB.get(l, i, j) = recB(l, i - 1, j) + recA(l - 1, i - 1, j - 1);
}

signed main() {
#ifndef LOCAL
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
#else
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int n, s, f;
    cin >> n >> s >> f;
    s--, f--;

    cout << (recA(n, s, f) + recB(n, s, f)).value << '\n';
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Subtask #1:

score: 6
Accepted

Test #1:

score: 6
Accepted
time: 8ms
memory: 70312kb

input:

7 3 6

output:

14

result:

ok 1 number(s): "14"

Subtask #2:

score: 30
Accepted

Dependency #1:

100%
Accepted

Test #2:

score: 30
Accepted
time: 0ms
memory: 70380kb

input:

39 36 32

output:

964903316

result:

ok 1 number(s): "964903316"

Test #3:

score: 0
Accepted
time: 4ms
memory: 70572kb

input:

26 1 26

output:

955348527

result:

ok 1 number(s): "955348527"

Test #4:

score: 0
Accepted
time: 3ms
memory: 70616kb

input:

40 11 33

output:

695661890

result:

ok 1 number(s): "695661890"

Test #5:

score: 0
Accepted
time: 17ms
memory: 70536kb

input:

39 39 38

output:

717149364

result:

ok 1 number(s): "717149364"

Test #6:

score: 0
Accepted
time: 4ms
memory: 70408kb

input:

40 10 25

output:

912929610

result:

ok 1 number(s): "912929610"

Test #7:

score: 0
Accepted
time: 7ms
memory: 70380kb

input:

37 25 23

output:

250748685

result:

ok 1 number(s): "250748685"

Test #8:

score: 0
Accepted
time: 7ms
memory: 70316kb

input:

39 2 38

output:

624060592

result:

ok 1 number(s): "624060592"

Test #9:

score: 0
Accepted
time: 0ms
memory: 70400kb

input:

40 18 22

output:

739993796

result:

ok 1 number(s): "739993796"

Test #10:

score: 0
Accepted
time: 0ms
memory: 70616kb

input:

40 11 35


output:

135213497

result:

ok 1 number(s): "135213497"

Subtask #3:

score: 15
Accepted

Dependency #1:

100%
Accepted

Dependency #2:

100%
Accepted

Test #11:

score: 15
Accepted
time: 4ms
memory: 70324kb

input:

199 100 70

output:

914653136

result:

ok 1 number(s): "914653136"

Test #12:

score: 0
Accepted
time: 4ms
memory: 70580kb

input:

187 3 40

output:

928785584

result:

ok 1 number(s): "928785584"

Test #13:

score: 0
Accepted
time: 0ms
memory: 70564kb

input:

199 198 197

output:

38412688

result:

ok 1 number(s): "38412688"

Test #14:

score: 0
Accepted
time: 8ms
memory: 70352kb

input:

200 40 140

output:

367088143

result:

ok 1 number(s): "367088143"

Test #15:

score: 0
Accepted
time: 0ms
memory: 70584kb

input:

199 111 3

output:

870834793

result:

ok 1 number(s): "870834793"

Test #16:

score: 0
Accepted
time: 11ms
memory: 70552kb

input:

200 133 73

output:

343127012

result:

ok 1 number(s): "343127012"

Test #17:

score: 0
Accepted
time: 3ms
memory: 70356kb

input:

178 15 163

output:

160852284

result:

ok 1 number(s): "160852284"

Test #18:

score: 0
Accepted
time: 0ms
memory: 70396kb

input:

197 43 79

output:

332057544

result:

ok 1 number(s): "332057544"

Test #19:

score: 0
Accepted
time: 7ms
memory: 70556kb

input:

200 33 79

output:

742545318

result:

ok 1 number(s): "742545318"

Subtask #4:

score: 49
Accepted

Dependency #1:

100%
Accepted

Dependency #2:

100%
Accepted

Dependency #3:

100%
Accepted

Test #20:

score: 49
Accepted
time: 11ms
memory: 70324kb

input:

658 169 438

output:

206087110

result:

ok 1 number(s): "206087110"

Test #21:

score: 0
Accepted
time: 11ms
memory: 70364kb

input:

700 207 509

output:

478311263

result:

ok 1 number(s): "478311263"

Test #22:

score: 0
Accepted
time: 7ms
memory: 70372kb

input:

755 139 507

output:

103783948

result:

ok 1 number(s): "103783948"

Test #23:

score: 0
Accepted
time: 36ms
memory: 70696kb

input:

2000 500 1500

output:

123410309

result:

ok 1 number(s): "123410309"

Test #24:

score: 0
Accepted
time: 46ms
memory: 70464kb

input:

2000 1000 1001

output:

956197482

result:

ok 1 number(s): "956197482"

Test #25:

score: 0
Accepted
time: 39ms
memory: 70468kb

input:

2000 666 1333

output:

993781645

result:

ok 1 number(s): "993781645"

Test #26:

score: 0
Accepted
time: 31ms
memory: 70544kb

input:

1991 198 677

output:

155058730

result:

ok 1 number(s): "155058730"

Test #27:

score: 0
Accepted
time: 21ms
memory: 70516kb

input:

1498 299 659

output:

665757882

result:

ok 1 number(s): "665757882"