Search for a command to run...
Progressive hints first, then the full explanation and implementation when you're ready to cash out.
Review status
AI-generated and still unreviewed. Double-check the details before internalizing them.
Hints
Open only as much as you need to keep the solve alive.
Think about whether player ever has to play a match. If we only need the last players, maybe we can just leave them alone.
When , there is room for player plus at least one other player at the end. That means we only need to eliminate players from the other people.
For , while the tournament has more than players, there are always at least two players other than available to fight. So player can completely dodge the chaos.
The only actually dangerous case is , because then player must be the sole winner. Dodging forever is no longer an option.
For , player can win iff no one has strictly larger strength than . Equivalently, must be equal to the maximum value in the array.
There are two very different cases hiding here. The problem looks like a tournament simulation, but simulating it would be pointless. The choices are flexible, and we only need to know whether some sequence can keep player alive.
Key observation
A player is eliminated only if they are chosen for a match.
So if we can avoid choosing player until the tournament stops, then player survives. Simple. Kinda stupid, but in the best Codeforces way.
Case 1:
We need player to be among the last remaining players, not necessarily the winner.
So we can try this strategy:
Initially there are players other than .
We need to eliminate exactly players total. Since , we have:
So we do not need to eliminate all other players. At least one non- player can remain with player at the end.
Also, whenever the tournament still needs another elimination, there are more than players remaining. Since player is still present, the number of other players is more than . Because , that means there are at least two other players available to fight.
Therefore, for , player can always survive. Strengths do not matter at all. The whole array is basically decorative furniture.
So:
Case 2:
Now player must be the final remaining player. They cannot just hide in a corner until the end, because everyone else must eventually be eliminated.
If some player has strength strictly greater than , then that stronger player cannot be eliminated by player . Even worse, the strongest player overall can never be eliminated by someone weaker. To make player the winner, every stronger player would need to disappear somehow, but nobody weaker can eliminate them.
So if there exists some , player cannot win.
On the other hand, if is equal to the maximum strength in the array, then player can win. Any weaker player loses to them, and players with equal strength can be eliminated randomly. Since the question asks whether there is any way, ties can go in player 's favor.
So for :
Algorithm
For each test case:
YES.YES iff is the maximum array value.Complexity
Each test case takes time to read and find the maximum.
Total complexity is:
which easily fits the limits.
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void setIO() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
}
int main() {
setIO();
int t;
cin >> t;
while (t--) {
int n, j, k;
cin >> n >> j >> k;
vector<int> a(n);
for (int &x : a) cin >> x;
int player = a[j - 1];
int best = *max_element(a.begin(), a.end());
if (k > 1 || player == best) cout << "YES\n";
else cout << "NO\n";
}
}#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void setIO() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
}
int main() {
setIO();
int t;
cin >> t;
while (t--) {
int n, j, k;
cin >> n >> j >> k;
vector<int> a(n);
for (int &x : a) cin >> x;
int player = a[j - 1];
int best = *max_element(a.begin(), a.end());
if (k > 1 || player == best) cout << "YES\n";
else cout << "NO\n";
}
}