Submission #1075343


Source Code Expand

#include <bits/stdc++.h>

using namespace std;

typedef long double ld;
typedef long long ll;

const int mod = 1e9 + 7;

int add(int x, int y) {
  x += y;
  if (x >= mod)
    x -= mod;
  return x;
}

int udd(int &x, int y) {
  return x = add(x, y);
}

int sub(int x, int y) {
  return add(x, mod - y);
}

int uub(int &x, int y) {
  return x = sub(x, y);
}

const int M = 4020;

int d[M][M];
int n, m, k;

void calc() {
  d[0][0] = 1;
  for (int len = 1; len < M; ++len) {
    int cur = 0;
    for (int sum = 0; sum < M; ++sum) {
      cur = add(cur, d[len - 1][sum]);
      if (sum >= k)
        cur = sub(cur, d[len - 1][sum - k]);
      d[len][sum] = cur;
    }
  }
}

void read() {
  cin >> n >> m >> k;
}

void kill() {
  int ans = 0;
  for (int sb = 1; sb <= m; ++sb)
    if (sb % (k - 1) == m % (k - 1)) {
      int len = (n + sb - 1) / (k - 1);
      ans = add(ans, d[len][sb]);
    }

  cout << ans << endl;
}

int main() {
#ifdef LOCAL
  assert(freopen("e.in", "r", stdin));
#endif

  ios_base::sync_with_stdio(false);

  read();
  calc();
  kill();
}

Submission Info

Submission Time
Task E - Eternal Average
User Arterm
Language C++14 (GCC 5.4.1)
Score 1600
Code Size 1135 Byte
Status AC
Exec Time 107 ms
Memory 63360 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 1600 / 1600
Status
AC × 3
AC × 27
Set Name Test Cases
Sample s1.txt, s2.txt, s3.txt
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, 23.txt, 24.txt, s1.txt, s2.txt, s3.txt
Case Name Status Exec Time Memory
01.txt AC 106 ms 63360 KB
02.txt AC 106 ms 63360 KB
03.txt AC 106 ms 63360 KB
04.txt AC 106 ms 63360 KB
05.txt AC 106 ms 63360 KB
06.txt AC 106 ms 63360 KB
07.txt AC 106 ms 63360 KB
08.txt AC 106 ms 63360 KB
09.txt AC 106 ms 63360 KB
10.txt AC 106 ms 63360 KB
11.txt AC 100 ms 63360 KB
12.txt AC 96 ms 63360 KB
13.txt AC 105 ms 63360 KB
14.txt AC 105 ms 63360 KB
15.txt AC 106 ms 63360 KB
16.txt AC 96 ms 63360 KB
17.txt AC 103 ms 63360 KB
18.txt AC 106 ms 63360 KB
19.txt AC 106 ms 63360 KB
20.txt AC 107 ms 63360 KB
21.txt AC 107 ms 63360 KB
22.txt AC 106 ms 63360 KB
23.txt AC 106 ms 63360 KB
24.txt AC 106 ms 63360 KB
s1.txt AC 106 ms 63360 KB
s2.txt AC 106 ms 63360 KB
s3.txt AC 106 ms 63360 KB