Create help.cpp

Changes

1 changed files (+116/-0)

• 2020/February/help.cpp (new)
  • @@ -0,0 +1,116 @@
    + #include <bits/stdc++.h> + #include <ext/pb_ds/tree_policy.hpp> + #include <ext/pb_ds/assoc_container.hpp> + #include <ext/rope> + #define init_io(s) ifstream cin((string)s+".in"); ofstream cout((string)s+".out"); ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL) + #define FOR(i, a, b, in) for (int i = (a); i < (b); i += in) + #define REP(i, a, b) for (int i = (a); i < (b); i++) + #define RFOR(i, a, b, in) for (int i = (a) - 1; i >= (b); i -= in) + #define RREP(i, a, b) for (int i = (a) - 1; i >= (b); i--) + #define trav(a, x) for (auto& a : x) + #define mp make_pair + #define pb push_back + #define eb emplace_back + #define f first + #define s second + #define lb lower_bound + #define ub upper_bound + #define sz(x) (int)x.size() + #define all(x) begin(x), end(x) + #define rsz resize + #define mem(a, b) memset(a, (b), sizeof(a)) + using namespace std; + using namespace __gnu_pbds; + using namespace __gnu_cxx; + typedef string str; + typedef long long ll; + typedef long double ld; + typedef complex<ld> cd; + typedef pair<int, int> ii; typedef pair<ll, ll> pl; typedef pair<ld, ld> pd; + typedef vector<int> vi; typedef vector<ll> vl; typedef vector<ld> vd; + typedef vector<ii> vii; typedef vector<pl> vpl; typedef vector<pd> vpd; + typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; + typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset; // WARNING: May be broken + constexpr int INF = 1e9; + constexpr ll LINF = 1e18; + constexpr ll MOD = 1e9+7; + const ld PI = 4*atan((ld)1); + + inline int imod(int i) { return i > MOD ? i - MOD : i; } + + int N, pow2[100005] = { 1 }; + ii S[100005]; + struct seg_tree { + int seg[800005] = { 0 }, tmp[800005] = { 0 }; + void pull(int n) { seg[n] = imod(seg[n<<1]+seg[n<<1|1]); } + void push(int l, int r, int n) { + seg[n] = ((ll)pow2[tmp[n]]*seg[n])%MOD; + if (l != r) tmp[n<<1] += tmp[n], tmp[n<<1|1] += tmp[n]; + tmp[n] = 0; + } + void update(int x, int v, int l = 1, int r = -1, int n = 1) { + if (r == -1) r = 2*N; + if (tmp[n]) push(l, r, n); + if (l == r) seg[n] = imod(v+seg[n]); + else { + int m = (l + r) >> 1; + x <= m ? update(x, v, l, m, n<<1) : update(x, v, m + 1, r, n<<1|1); + pull(n); + } + } + void update_range(int a, int b, int l = 1, int r = -1, int n = 1) { + if (r == -1) r = 2*N; + if (tmp[n]) push(l, r, n); + if (l > b || r < a) return; + if (l >= a && r <= b) { + tmp[n]++; + push(l, r, n); + } + else { + int m = (l + r) >> 1; + update_range(a, b, l, m, n<<1), update_range(a, b, m + 1, r, n<<1|1); + pull(n); + } + } + int query(int a, int b, int l = 1, int r = -1, int n = 1) { + if (r == -1) r = 2*N; + if (a > b || l > b || r < a) return 0; + if (tmp[n]) push(l, r, n); + if (l >= a && r <= b) return seg[n]; + int m = (l + r) >> 1; + return imod(query(a, b, l, m, n<<1) + query(a, b, m + 1, r, n<<1|1)); + } + } dp[11]; + + int main() { + init_io("help"); + + int fact[11] = { 1 }, nCr[11][11]; + for (int i = 0; i < 10; i++) fact[i+1] = (i+1)*fact[i]; + for (int i = 0; i <= 10; i++) { + for (int j = 0; j <= i; j++) nCr[i][j] = fact[i]/fact[j]/fact[i-j]; + } + for (int i = 0; i < 100000; i++) pow2[i+1] = imod(pow2[i]<<1); + + int K; + cin >> N >> K; + for (int i = 0; i < N; ++i) cin >> S[i].f >> S[i].s; + sort(S, S + N); + + for (int i = 0; i < N; ++i) { + int tmp[11]; + for (int j = 0; j <= K; ++j) { + tmp[j] = dp[j].query(1, S[i].f); + ll sum = dp[j].query(S[i].f, S[i].s-1); + for (int k = 0; k <= j; ++k) { + sum += (ll)nCr[j][k]*tmp[k]; + } + dp[j].update(S[i].s, sum%MOD+1); + } + for (int j = 0; j <= K; ++j) { + dp[j].update_range(S[i].s+1, 2*N); + } + } + + cout << dp[K].query(1, 2*N) << endl; + }