Submission #5641879

Source Code Expand

#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define mp make_pair
#define fs first
#define sc second

int n, m, k;
const int mod = 1e9 + 7;

long long res2() {
  long long num = m - 1;
  long long res_x = 0, res_y = 0;
  res_x = (long long)((num + 1) * (2 * num + 4) * num / 12) % mod;
  res_x = res_x * n * n % mod;

  num = n - 1;
  res_y = (long long)((num + 1) * (2 * num + 4) * num / 12) % mod;
  res_y = res_y * m * m % mod;
  return (res_x + res_y) % mod;
}

long long comb(int a, int b) {
  long long res = 1;
  long long top = 1, bot = 1;
  for (int i = 0; i < b; ++i) {
    top = top * (a - i) % mod;
    bot = bot * (b - i) % mod;
  }

  long long binpow = mod - 2, botinv = 1;
  while (binpow) {
    if (binpow & 1)
      botinv = botinv * bot % mod;
    bot = bot * bot % mod;
    binpow >>= 1;
  }
  return (top * botinv) % mod;
}

int main() {
  cin >> n >> m >> k;
  long long res_2 = res2();
  cout << res_2 * comb(n * m - 2, k - 2) % mod << endl;
  return 0;
}

Submission Info

Submission Time
Task E - Cell Distance
User bcoskun
Language C++14 (GCC 5.4.1)
Score 500
Code Size 1051 Byte
Status AC
Exec Time 2 ms
Memory 256 KiB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 500 / 500
Status AC
AC × 25
Set Name Test Cases
Sample
All 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, 13.txt, 14.txt, 15.txt, 16.txt, 17.txt, 18.txt, 19.txt, 20.txt, 21.txt, 22.txt, s1.txt, s2.txt, s3.txt
Case Name Status Exec Time Memory
01.txt AC 1 ms 256 KiB
02.txt AC 1 ms 256 KiB
03.txt AC 1 ms 256 KiB
04.txt AC 1 ms 256 KiB
05.txt AC 1 ms 256 KiB
06.txt AC 1 ms 256 KiB
07.txt AC 1 ms 256 KiB
08.txt AC 2 ms 256 KiB
09.txt AC 1 ms 256 KiB
10.txt AC 2 ms 256 KiB
11.txt AC 1 ms 256 KiB
12.txt AC 1 ms 256 KiB
13.txt AC 2 ms 256 KiB
14.txt AC 1 ms 256 KiB
15.txt AC 1 ms 256 KiB
16.txt AC 2 ms 256 KiB
17.txt AC 2 ms 256 KiB
18.txt AC 2 ms 256 KiB
19.txt AC 1 ms 256 KiB
20.txt AC 1 ms 256 KiB
21.txt AC 2 ms 256 KiB
22.txt AC 2 ms 256 KiB
s1.txt AC 1 ms 256 KiB
s2.txt AC 1 ms 256 KiB
s3.txt AC 1 ms 256 KiB