#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
int add (int a, int b) {
a += b; if (a >= MOD) a -= MOD;
return a;
}
int sub (int a, int b) {
a -= b; if (a < 0) a += MOD;
return a;
}
int mul (int a, int b) {
return (a * 1ll * b) % MOD;
}
const int MAXN = 5e5 + 25;
int dp[MAXN][27];
int n, m;
vector <int> type1[MAXN];
vector <int> type2[MAXN];
int ans (int pos, int c) {
int &ret = dp[pos][c];
if (ret != -1) return ret;
if (pos == 1) return ret = 1;
ret = 0;
for (int j = 0; j < c; j++) {
bool flag = 1;
for (int i = pos - 1; i >= 1; i--) {
for (auto k : type2[i - 1]) {
flag &= (pos > k);
}
if (flag) ret = add(ret, ans(i, j));
}
}
for (int j = c + 1; j < 26; j++) {
bool flag = 1;
for (int i = pos - 1; i >= 1; i--) {
for (auto k : type2[i - 1]) {
flag &= (pos > k);
}
if (flag) ret = add(ret, ans(i, j));
}
}
return ret;
}
int main () {
memset(dp, -1, sizeof(dp));
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int a, b;
cin >> a >> b;
int l = min(a, b), r = max(a, b);
if (a > b) {
type1[l - 1].push_back(r);
} else {
type2[l - 1].push_back(r);
}
}
int sum = 0;
for (int i = 0; i < 26; i++) {
for (int j = 1; j <= n; j++) {
sum = add(sum, ans(j, i));
}
}
cout << sum << '\n';
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
12 ms |
76636 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
12 ms |
76636 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
12 ms |
76636 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
12 ms |
76636 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
12 ms |
76636 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
