Submission #1096080

#	Time	Username	Problem	Language	Result	Execution time	Memory
1096080		andrewp	Martian DNA (BOI18_dna)	C++14	68 / 100	2050 ms	18036 KiB

dna

//Dedicated to my love, ivaziva
#pragma GCC optimize("Ofast") 
#include <bits/stdc++.h> 
using namespace std;   
 
using pii = pair<int, int>;
using ll = int64_t;  
  
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define pb push_back 
#define dbg(x) cerr<<#x<<": "<<x<<'\n';  
#define dbga(A,l_,r_){for(int i_=l_;i_<=r_;i_++)cerr<<A[i_]<<' ';cerr<<'\n';}
#define dbgv(a_){for(auto x_:a_) cerr<<x_<<' ';cerr<<'\n';}   

const int maxn = 2e5 + 3;
int n, k, r;
int a[maxn], b[maxn], q[maxn], ps[maxn][20]; 

bool check(int len) {  
    for (int i = len; i <= n; i++) {
        bool ok = true;
        for (int j = 1; j <= r; j++) {
            if (ps[i][j] - ps[i - len][j] < q[j]) { 
                ok = false;
            }
        }
        if (ok) {
            return true;
        }
    } 
    return false;
}
 
int32_t main()  {
    ios::sync_with_stdio(false); cin.tie(nullptr);  
    cout.tie(nullptr); cerr.tie(nullptr);

    cin >> n >> k >> r;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for (int i = 1; i <= r; i++) { 
        cin >> b[i] >> q[i]; 
    }   
    for (int j = 1; j <= r; j++) {
        ps[0][j] = 0; 
    } 
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= r; j++) { 
            ps[i][j] = ps[i - 1][j] + (a[i] == b[j]);
        }
    }
    int l = 1, r = n, ans = -1;
    while (l <= r) {
        int mid = (l + r) / 2;
        if (check(mid)) {
            r = mid - 1;
            ans = mid;
        } else {
            l = mid + 1;
        }
    }
    if (ans == -1) {
        cout << "impossible\n";
        return 0;
    }
    cout << ans << '\n'; 
    return 0;   
}

• Subtask 1: 16 / 16
• Subtask 2: 24 / 24
• Subtask 3: 28 / 28
• Subtask 4: 0 / 32