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Submission #1087063

# Submission time Handle Problem Language Result Execution time Memory
1087063 2024-09-12T07:11:34 Z pokmui9909 Sparklers (JOI17_sparklers) C++17
0 / 100
 0 ms 348 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

ll N, K, T, A[100005], B[100005];

bool f(ll v){
    for(ll i = 1; i <= N; i++){
        B[i] = A[i] - 2 * v * T * i;
    }
    ll gl = K, gr = K;
    for(ll i = 1; i <= N; i++){
        if(i <= K && B[gl] <= B[i]) gl = i;
        if(i >= K && B[gr] >= B[i]) gr = i;
    }
    ll l = K, r = K;
    while(1){
        ll ch = 0, nl = l, nr = r;
        while(nl > gl && B[nl - 1] >= B[r]) nl--;
        if(B[nl] >= B[l] && nl < l){
            l = nl, ch = 1;
        }

        while(nr < gr && B[nr + 1] <= B[l]) nr++;
        if(B[nr] <= B[r] && nr > r){
            r = nr, ch = 1;
        }
        if(ch == 0) break;
    }
    if(l != gl || r != gr) return 0;
    l = 1, r = N;
    if(B[l] < B[r]) return 0;
    while(1){
        ll ch = 0, nl = l, nr = r;
        while(nl < gl && B[nl + 1] >= B[r]) nl++;
        if(B[nl] >= B[l] && nl > l){
            l = nl, ch = 1;
        }

        while(nr > gr && B[nr - 1] <= B[l]) nr--;
        if(B[nr] <= B[r] && nr < r){
            r = nr, ch = 1;
        }
        if(ch == 0) break;
    }
    return (l == gl && r == gr);
}

int main(){
    cin.tie(0) -> sync_with_stdio(0);

    cin >> N >> K >> T;
    for(ll i = 1; i <= N; i++){
        cin >> A[i];
    }
    if(A[N] == 0){
        cout << 0; return 0;
    }
    ll L = 1, R = 1e9;
    while(L <= R){
        ll m = (L + R) / 2;
        if(f(m)) R = m - 1;
        else L = m + 1;
    }
    cout << L;
}

Subtask #1
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Incorrect 0 ms 348 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Incorrect 0 ms 348 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Incorrect 0 ms 348 KB Output isn't correct
11 Halted 0 ms 0 KB -