Submission #1260333

#	Time	Username	Problem	Language	Result	Execution time	Memory
1260333		am_aadvik	Triple Peaks (IOI25_triples)	C++20	35 / 100	2096 ms	1984 KiB

triples

#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
using namespace std;

bool check(int i, int j, int k, vector<int>& a) {
	if (!((i < j) && (j < k))) return 0;
	if((j < 0) || ((j >= a.size()))) return 0;
	vector<int> x = { j - i, k - i, k - j };
	vector<int> y = { a[i], a[j], a[k] };
	sort(x.begin(), x.end());
	sort(y.begin(), y.end());
	for (int i = 0; i < 3; ++i)
		if (x[i] != y[i]) return 0;
	return 1;
}
int find(int i, int k, vector<int>&a) {
	if ((k < 0) || ((k >= a.size()))) return 0;
	if ((i < 0) || ((i >= a.size()))) return 0;
	vector<int> op = { i + a[i],
		k - a[i], i + a[k], k - a[k] };
	set<int> s;
	for (auto x : op) s.insert(x);
	int ans = 0;
	for (auto j : s)
		ans += (check(i, j, k, a));
	return ans;
}
int count_triples(vector<int> a) {
	int mx = a[0], ok = 1;
	for (int i = 1; i < a.size(); ++i)
		mx = max(mx, a[i]),
		ok &= (a[i] >= a[i - 1]);

	int ans = 0, n = a.size();
	for (int k = 0; k < n; ++k) {
		int s = (ok ? k - a[k] : max(0, k - mx - 5));
		int e = (ok ? k - a[k] : k - 2);
		for (int i = s; i <= e; ++i)
			ans += find(i, k, a);
	}
	return ans;
}
vector<int> construct_range(int M, int K) {
	vector<int> a; return a;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 6 / 6
• Subtask 3: 10 / 10
• Subtask 4: 11 / 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