Submission #880590

#	Time	Username	Problem	Language	Result	Execution time	Memory
880590		tsumondai	Izbori (COCI22_izbori)	C++14	10 / 110	212 ms	11484 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define __TIME  (1.0 * clock() / CLOCKS_PER_SEC)

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
 
const int N = 1e6 + 5, BLOCK_SIZE=450;
 
const int oo = 1e9, mod = 1e9 + 7;
 
int n, m, k, a[N], cnt[N], mp[N], s[N], t[N];
vector<int> arr;

void update(int pos, int val){
    for (int i=pos; i<BLOCK_SIZE; i+=i&(-i)) t[i]+=val;
}
 
int get(int pos){
    if (pos<0) return 0;
    int sum=0;
    for (int i=pos; i; i-=i&(-i)) sum+=t[i];
    return sum;
}

void process() {
	cin >> n;
    long long ans=0;
    for (int i=1; i<=n; ++i) cin >> a[i];
    vector<int> sus(a+1, a+n+1);
    sort(sus.begin(),sus.end()); sus.resize(unique(sus.begin(),sus.end())-sus.begin());
    for (int i=1; i<=n; ++i) a[i]=lower_bound(sus.begin(),sus.end(), a[i])-sus.begin()+1;
    for (int i=1; i<=n; ++i) ++mp[a[i]];
    for (int l=1; l<=n; ++l){
        int mx=0;
        for (int r=l; r<=n && r-l+1<=2*BLOCK_SIZE; ++r){
            if (mp[a[r]]<=BLOCK_SIZE){
                ++cnt[a[r]];
                mx=max(mx, cnt[a[r]]);
            }
            if (mx*2>r-l+1) ++ans;
        }
        for (int r=l; r<=n && r-l+1<=2*BLOCK_SIZE; ++r){
            if (mp[a[r]]<=BLOCK_SIZE) --cnt[a[r]];
        }
    }
    for (int i=1; i<=n; ++i){
        if (mp[i]<=BLOCK_SIZE) continue;
        memset(s, 0, sizeof s);
        memset(t, 0, sizeof t);
        for (int j=1; j<=n; ++j) if (a[j]==i) ++s[j]; else --s[j];
        partial_sum(s, s+n+1, s);
        update(0+n+1, 1);
        for (int j=1; j<=n; ++j){
            ans+=get(s[j]-1+n+1);
            update(s[j]+n+1, 1);
        }
    }
    cout << ans;
    return;
}

signed main() {
    cin.tie(0)->sync_with_stdio(false);
    //freopen(".inp", "r", stdin);
    //freopen(".out", "w", stdout);
    process();
    cerr << "Time elapsed: " << __TIME << " s.\n";
    return 0;
}

/*
Xét các trường hợp đặc biệt
Kiểm tra lại input/output
Cố gắng trâu
Lật ngược bài toán
Keep calm and get VOI 
Flow:

*/

• Subtask 1: 10 / 10
• Subtask 2: 0 / 15
• Subtask 3: 0 / 15
• Subtask 4: 0 / 70