Submission #43917594

Source Code Expand

#include <bits/stdc++.h>
#include <atcoder/modint.hpp>

void solve(std::istream& is, std::ostream& os) {
    using Num = long long int;
    using ModInt = atcoder::modint1000000007;
    Num n {0};
    Num k {0};
    is >> n >> k;

    ModInt answer {1};
    ModInt a {1};
    ModInt b {1};
    for(Num i{1}; i<=std::min(n, k); ++i) {
        a *= (n-i+1);
        a /= i;
        b *= (n-i);
        b /= i;
        answer += a * b;
    }

    os << answer.val() << "\n";
    return;
}

int main(void) {
    solve(std::cin, std::cout);
    return 0;
}

Submission Info

Submission Time
Task E - Roaming
User zettsut
Language C++ (GCC 9.2.1)
Score 500
Code Size 581 Byte
Status AC
Exec Time 55 ms
Memory 3632 KiB

Judge Result

Set Name All Sample
Score / Max Score 500 / 500 0 / 0
Status
AC × 29
AC × 3
Set Name Test Cases
All sample_01.txt, sample_02.txt, sample_03.txt, testcase_1.txt, testcase_10.txt, testcase_11.txt, testcase_12.txt, testcase_13.txt, testcase_14.txt, testcase_15.txt, testcase_16.txt, testcase_17.txt, testcase_18.txt, testcase_19.txt, testcase_2.txt, testcase_20.txt, testcase_21.txt, testcase_22.txt, testcase_23.txt, testcase_24.txt, testcase_25.txt, testcase_26.txt, testcase_3.txt, testcase_4.txt, testcase_5.txt, testcase_6.txt, testcase_7.txt, testcase_8.txt, testcase_9.txt
Sample sample_01.txt, sample_02.txt, sample_03.txt
Case Name Status Exec Time Memory
sample_01.txt AC 7 ms 3632 KiB
sample_02.txt AC 50 ms 3604 KiB
sample_03.txt AC 2 ms 3396 KiB
testcase_1.txt AC 2 ms 3596 KiB
testcase_10.txt AC 2 ms 3580 KiB
testcase_11.txt AC 1 ms 3568 KiB
testcase_12.txt AC 2 ms 3536 KiB
testcase_13.txt AC 2 ms 3608 KiB
testcase_14.txt AC 2 ms 3456 KiB
testcase_15.txt AC 2 ms 3456 KiB
testcase_16.txt AC 2 ms 3456 KiB
testcase_17.txt AC 37 ms 3448 KiB
testcase_18.txt AC 29 ms 3452 KiB
testcase_19.txt AC 9 ms 3532 KiB
testcase_2.txt AC 2 ms 3588 KiB
testcase_20.txt AC 36 ms 3596 KiB
testcase_21.txt AC 18 ms 3536 KiB
testcase_22.txt AC 18 ms 3632 KiB
testcase_23.txt AC 14 ms 3580 KiB
testcase_24.txt AC 2 ms 3536 KiB
testcase_25.txt AC 2 ms 3564 KiB
testcase_26.txt AC 33 ms 3452 KiB
testcase_3.txt AC 55 ms 3592 KiB
testcase_4.txt AC 49 ms 3600 KiB
testcase_5.txt AC 48 ms 3396 KiB
testcase_6.txt AC 51 ms 3528 KiB
testcase_7.txt AC 47 ms 3532 KiB
testcase_8.txt AC 2 ms 3588 KiB
testcase_9.txt AC 13 ms 3532 KiB