Submission #446480

#	Time	Username	Problem	Language	Result	Execution time	Memory
446480		dxz05	Martian DNA (BOI18_dna)	C++14	100 / 100	68 ms	4560 KiB

dna

#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define revall(x) (x).rbegin(), (x).rend()

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

#define MP make_pair

typedef long long ll;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.00001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 2e5 + 3e2;
const int M = 222;

int a[N];
int diff = 0;
int cnt[N], need[N];

void add(int i){
    int x = a[i];
    if (need[x] == 0) return;
    cnt[x]++;
    if (cnt[x] == need[x]) diff++;
}

void del(int i){
    int x = a[i];
    if (need[x] == 0) return;
    cnt[x]--;
    if (cnt[x] == need[x] - 1) diff--;
}

int n, k, q;

bool check(int len){
    fill(cnt, cnt + k, 0);
    diff = 0;
    for (int i = 1; i <= n; i++){
        add(i);
        if (i > len) del(i - len);
        if (diff == q) return true;
    }
    return false;
}

void solve(int TC) {
    cin >> n >> k >> q;

    for (int i = 1; i <= n; i++) cin >> a[i];

    for (int i = 1; i <= q; i++){
        int x, y;
        cin >> x >> y;
        need[x] = y;
    }

    int ans = -1;
    int l = 1, r = n;
    while (l <= r){
        int m = (l + r) >> 1;
        if (check(m)){
            ans = m;
            r = m - 1;
        } else l = m + 1;
    }

    if (ans == -1) cout << "impossible"; else
        cout << ans;

}

int main() {
    startTime = clock();
    cin.tie(nullptr); cout.tie(nullptr);
    ios_base::sync_with_stdio(false);

    bool llololcal = false;
#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    llololcal = true;
#endif

    int TC = 1;
    //cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

    if (llololcal) cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;

    return 0;
}

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