#include <bits/stdc++.h>
using namespace std;
const int N = 3003 * 3003;
const int md = 1e9 + 7;
int f[N], inv[N];
int add(int x, int y) {
return x + y < md ? x + y : x + y - md;
}
void sadd(int& x, int y) {
x = add(x, y);
}
int mul(int x, int y) {
return x * 1LL * y % md;
}
void smul(int& x, int y) {
x = mul(x, y);
}
int ckpow(int x, int k) {
int ret = 1;
while (k) {
if (k & 1) {
ret = mul(ret, x);
}
x = mul(x, x);
k >>= 1;
}
return ret;
}
int C(int n, int k) {
if (n < 0 || k < 0 || n < k) {
return 0;
}
return mul(f[n], mul(inv[k], inv[n - k]));
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
f[0] = 1;
for (int i = 1; i < N; i++) {
f[i] = mul(f[i - 1], i);
}
inv[N - 1] = ckpow(f[N - 1], md - 2);
for (int i = N - 2; i >= 0; i--) {
inv[i] = mul(inv[i + 1], i + 1);
}
int r, c;
cin >> r >> c;
int n;
cin >> n;
int lx = r, rx = -1, ly = c, ry = -1;
for (int i = 0; i < n; i++) {
int x, y;
cin >> x >> y;
lx = min(lx, x);
rx = max(rx, x);
ly = min(ly, y);
ry = max(ry, y);
}
int len_x = rx - lx + 1;
int len_y = ry - ly + 1;
int total = len_x * len_y - n;
vector<vector<int>> dp(r + 1, vector<int>(c + 1));
dp[len_x][len_y] = f[total];
for (int x = 1; x <= r; x++) {
for (int y = 1; y <= c; y++) {
if (x < r) {
sadd(dp[x + 1][y], mul(dp[x][y], f[y]));
}
if (y < c) {
sadd(dp[x][y + 1], mul(dp[x][y], f[x]));
}
}
}
int res = dp[r][c];
smul(res, C(r - len_x, lx - 1));
smul(res, C(c - len_y, ly - 1));
cout << res << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
116 ms |
70996 KB |
Output is correct |
2 |
Correct |
119 ms |
70996 KB |
Output is correct |
3 |
Correct |
118 ms |
70984 KB |
Output is correct |
4 |
Correct |
124 ms |
70984 KB |
Output is correct |
5 |
Correct |
124 ms |
70792 KB |
Output is correct |
6 |
Correct |
121 ms |
70776 KB |
Output is correct |
7 |
Correct |
120 ms |
70996 KB |
Output is correct |
8 |
Correct |
120 ms |
70876 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
117 ms |
70816 KB |
Output is correct |
2 |
Correct |
122 ms |
70800 KB |
Output is correct |
3 |
Correct |
121 ms |
70988 KB |
Output is correct |
4 |
Correct |
120 ms |
70996 KB |
Output is correct |
5 |
Correct |
127 ms |
70992 KB |
Output is correct |
6 |
Correct |
121 ms |
70892 KB |
Output is correct |
7 |
Correct |
122 ms |
70996 KB |
Output is correct |
8 |
Correct |
122 ms |
70996 KB |
Output is correct |
9 |
Correct |
124 ms |
71024 KB |
Output is correct |
10 |
Correct |
130 ms |
70920 KB |
Output is correct |
11 |
Correct |
123 ms |
70948 KB |
Output is correct |
12 |
Correct |
121 ms |
70976 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
123 ms |
71028 KB |
Output is correct |
2 |
Correct |
121 ms |
71252 KB |
Output is correct |
3 |
Correct |
124 ms |
71244 KB |
Output is correct |
4 |
Correct |
127 ms |
74324 KB |
Output is correct |
5 |
Correct |
128 ms |
74256 KB |
Output is correct |
6 |
Correct |
134 ms |
75600 KB |
Output is correct |
7 |
Correct |
133 ms |
77652 KB |
Output is correct |
8 |
Correct |
155 ms |
86556 KB |
Output is correct |
9 |
Correct |
210 ms |
106808 KB |
Output is correct |
10 |
Correct |
188 ms |
100436 KB |
Output is correct |
11 |
Correct |
191 ms |
100436 KB |
Output is correct |
12 |
Correct |
191 ms |
102996 KB |
Output is correct |
13 |
Correct |
126 ms |
73556 KB |
Output is correct |
14 |
Correct |
200 ms |
106284 KB |
Output is correct |
15 |
Correct |
206 ms |
107012 KB |
Output is correct |
16 |
Correct |
173 ms |
94692 KB |
Output is correct |
17 |
Correct |
203 ms |
106836 KB |
Output is correct |
18 |
Correct |
206 ms |
107356 KB |
Output is correct |