Submission #388555

#	Time	Username	Problem	Language	Result	Execution time	Memory
388555		talant117408	Boat (APIO16_boat)	C++17	31 / 100	1058 ms	135296 KiB

boat

/*
    Code written by Talant I.D.
*/
#include <bits/stdc++.h>
 
using namespace std;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
 
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
 
const int mod = 1e9+7;
 
ll mode(ll a) {
    a %= mod;
    if (a < 0) a += mod;
    return a;
}
 
ll subt(ll a, ll b) {
    return mode(mode(a)-mode(b));
}
 
ll add(ll a, ll b) {
    return mode(mode(a)+mode(b));
}
 
ll mult(ll a, ll b) {
    return mode(mode(a)*mode(b));
}
 
ll binpow(ll a, ll b) {
    ll res = 1;
    while (b) {
        if (b&1) res = mult(res, a);
        a = mult(a, a);
        b >>= 1;
    }
    return res;
}

const int N = 503;
int a[N], b[N], n;

bool subtask1() {
	int flag = 0;
	for (int i = 1; i <= n; i++) {
		if (a[i] == b[i]) flag++;
	}
	return flag == n;
}

bool subtask2() {
	ll sum = 0;
	for (int i = 1; i <= n; i++) {
		sum += b[i]-a[i];
	}
	return sum <= 1e6;
}

struct node {
	ll val;
	int lson, rson;
	node() {
		val = 0;
		lson = rson = -1;
	}
} tree[8000007];

int vertices = 1;

void create_lson(int v) {
	if (tree[v].lson == -1) {
		tree[v].lson = ++vertices;
	}
}

void create_rson(int v) {
	if (tree[v].rson == -1) {
		tree[v].rson = ++vertices;
	}
}

void update(int v, int l, int r, int pos, ll val) {
	if (l == r) {
		tree[v].val = add(tree[v].val, val);
		return;
	}
	int mid = (l+r) >> 1;
	create_lson(v);
	create_rson(v);
	if (pos <= mid) update(tree[v].lson, l, mid, pos, val);
	else update(tree[v].rson, mid+1, r, pos, val);
	tree[v].val = add(tree[tree[v].lson].val, tree[tree[v].rson].val);
}

ll get(int v, int l, int r, int ql, int qr) {
	if (l > qr || ql > r) return 0;
	if (ql <= l && r <= qr) return tree[v].val;
	int mid = (l+r) >> 1;
	create_lson(v);
	create_rson(v);
	return add(get(tree[v].lson, l, mid, ql, qr), get(tree[v].rson, mid+1, r, ql, qr));
}

int main() {
	do_not_disturb
	
    cin >> n;
    for (int i = 1; i <= n; i++) {
		cin >> a[i] >> b[i];
	}
	
	if (subtask1()) {
		vector <ll> dp(n+1);
		dp[0] = 1;
		for (int i = 1; i <= n; i++) {
			for (int j = i-1; j >= 0; j--) {
				if (a[i] > a[j]) {
					dp[i] = add(dp[i], dp[j]);
				}
			}
		}
		ll ans = 0;
		for (int i = 1; i <= n; i++) {
			ans = add(ans, dp[i]);
		}
		cout << ans << endl;
		return 0;
	}
	else if (subtask2()) {
		vector <vector <ll>> dp(n+1);
		dp[0].pb(1);
		update(1, 0, 1e9, 0, 1);
		ll ans = 0;
		
		for (int i = 1; i <= n; i++) {
			for (int j = a[i]; j <= b[i]; j++) {
				dp[i].pb(get(1, 0, 1e9, 0, j-1));
			}
			for (int j = a[i]; j <= b[i]; j++) {
				update(1, 0, 1e9, j, dp[i][j-a[i]]);
			}
		}
		
		for (int i = 1; i <= n; i++) {
			for (auto to : dp[i]) ans = add(ans, to);
		}
		
		cout << ans << endl;
		return 0;
	}
	
    return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 22 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42