Submission #1249874

#	Time	Username	Problem	Language	Result	Execution time	Memory
1249874		Zicrus	Triple Peaks (IOI25_triples)	C++20	18 / 100	2093 ms	1864 KiB

triples

#include <bits/stdc++.h>
#include "triples.h"
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define all(v) v.begin(), v.end()
constexpr ll inf = 1ll << 62ll;
mt19937 mt(time(0));
ll _ = 0;

bool valid(vector<int> &h, ll i, ll j, ll k) {
	if (j < i || k < i || k >= h.size()) return false;
	multiset<ll> dists = {abs(i-j), abs(j-k), abs(k-i)};
	multiset<ll> heights = {h[i], h[j], h[k]};
	return dists == heights;
}

ll count_triples(vector<int> h) {
	ll n = h.size();
	ll cnt = 0;
	for (ll i = 0; i < n; i++) {
		ll j = i + h[i];
		if (j < n && h[j] != h[i]) {
			if (i + h[j] != j + h[i]) cnt += valid(h, i, j, i + h[j]);
			if (i + h[j] != j - h[j]) cnt += valid(h, i, j, j - h[j]);
			cnt += valid(h, i, j, j + h[j]);
		}
		for (j = i+1; j + h[i] < n; j++) {
			ll k = j + h[i];
			cnt += valid(h, i, j, k);
		}
	}
	return cnt;
}

vector<int> construct_range(int M, int K) {
	return {};
}

#ifdef TEST
#include "grader.cpp"
#endif

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 0 / 6
• Subtask 3: 10 / 10
• Subtask 4: 0 / 11
• Subtask 5: 0 / 16
• Subtask 6: 0 / 19
• Subtask 7: 0 / 5
• Subtask 8: 0 / 5
• Subtask 9: 0 / 5
• Subtask 10: 0 / 5
• Subtask 11: 0 / 5
• Subtask 12: 0 / 5