Submission #764027

#	Time	Username	Problem	Language	Result	Execution time	Memory
764027		vjudge1	Fountain (eJOI20_fountain)	C++17	60 / 100	1578 ms	6220 KiB

fountain

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
#define len(x) (int)x.size()
#define ull unsigned long long
#define F first
#define S second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define int long long

using namespace std;
using namespace __gnu_pbds;
using ll = long long;

const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
int n,q,a[N],b[N],p[N];
bool ok = 1;

main(){
	// freopen("txt.in", "r", stdin);
	// freopen("txt.out", "w", stdout);
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n >> q;
	for (int i=1;i<=n;i++){
		cin >> a[i] >> b[i];
		if (a[i] < a[i-1]){
			ok = 0;
		}
	}
	if (ok){
		for (int i=1;i<=n;i++){
			p[i] = p[i-1] + b[i];
		}
		while(q--){
			int x,y;
			cin >> x >> y;
			int l = x;
			int r = n;
			while(l<=r){
				int md = (l + r) / 2;
				if (p[md] - p[x-1] < y){
					l = md + 1;
				}
				else{
					r = md - 1;
				}
			}
			if (p[n] - p[x-1] < y) cout << 0 << '\n';
			else cout << l << '\n';
		}
	}
	else{
		while(q--){
			int x,y;
			cin >> x >> y;
			int act = 0,cnt = 0;
			bool w = 0;
			for (int i=x;i<=n;i++){
				if (a[i] > act){
					act = a[i];
					cnt += b[i];
				}
				if (cnt >= y){
					cout << i << '\n';
					w = 1;
					break;
				}
			}
			if (!w) cout << 0 << '\n';
		}
	}
}

//order_of_key(k): Number of items strictly smaller than k .
//find_by_order(k): K-th element in a set (counting from zero).

//sum of squares n*(n+1)*(2n+1)/6
//sum of cubes [n*(n+1)/2]^2
//sum of squares for odds n*(4*n*n-1)/3
//sum of cubes for odds n*n*(2*n*n-1)

//a/b%mod = a*(b^(m-2)%mod)
//(a>>x)&1 == 0
//a^b = (a+b)-2(a&b)

//srand(time(0))-always changing

Compilation message (stderr)

fountain.cpp:27:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   27 | main(){
      | ^~~~

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 0 / 40