Submission #941709

#	Time	Username	Problem	Language	Result	Execution time	Memory
941709		phoenix0423	Martian DNA (BOI18_dna)	C++17	100 / 100	42 ms	4688 KiB

dna

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define fastio ios::sync_with_stdio(false), cin.tie(0)
#pragma GCC optimize("Ofast")
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define lowbit(x) x&-x
const int maxn = 2e5 + 5;
int req[maxn];

signed main(void){
    fastio;
    int n, k, r;
    cin>>n>>k>>r;
    vector<int> a(n);
    for(int i = 0; i < n; i++) cin>>a[i];
    for(int i = 0; i < r; i++){
        int b, t;
        cin>>b>>t;
        req[b] = t;
    }
    int L = 0, R = n + 1;
    while(L + 1 < R){
        int m = (L + R) / 2;
        int ok = k - r;
        vector<int> cur(k);
        for(int i = 0; i < m; i++){
            cur[a[i]] ++;
            if(cur[a[i]] == req[a[i]]) ok++;
        }
        if(ok == k){
            R = m;
            continue;
        }
        int pass = 0;
        for(int i = m; i < n; i++){
            cur[a[i]] ++;
            if(cur[a[i]] == req[a[i]]) ok++;
            cur[a[i - m]] --;
            if(cur[a[i - m]] == req[a[i - m]] - 1) ok--;
            if(ok == k) pass = 1;
        }
        if(pass) R = m;
        else L = m;
    }
    if(R == n + 1) cout<<"impossible\n";
    else cout<<R<<"\n";
}

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