Submission #832093

#	Time	Username	Problem	Language	Result	Execution time	Memory
832093		QwertyPi	Diversity (CEOI21_diversity)	C++14	18 / 100	66 ms	3832 KiB

diversity

#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define int long long
using namespace std;

const int MAXN = 3e5 + 11;
const int MAXQ = 5e4 + 11;
const int SQ = 1000;
int a[MAXN];
int ans[MAXQ];
int c[MAXN], cc[MAXN];

int s0, s1, s2;
set<int> s;
void add(int x){
    s0 -= c[x] * (c[x] + 1) / 2;
    s1 -= c[x];
    s2 -= c[x] * c[x];
    cc[c[x]]--; if(cc[c[x]] == 0) s.erase(c[x]);
    c[x]++;
    s0 += c[x] * (c[x] + 1) / 2;
    s1 += c[x];
    s2 += c[x] * c[x];
    cc[c[x]]++; if(cc[c[x]] == 1) s.insert(c[x]);
}

void rem(int x){
    s0 -= c[x] * (c[x] + 1) / 2;
    s1 -= c[x];
    s2 -= c[x] * c[x];
    cc[c[x]]--; if(cc[c[x]] == 0) s.erase(c[x]);
    c[x]--;
    s0 += c[x] * (c[x] + 1) / 2;
    s1 += c[x];
    s2 += c[x] * c[x];
    cc[c[x]]++; if(cc[c[x]] == 1) s.insert(c[x]);
}

int f(int x0, int d, int y, int n){
    return n * d * (x0 * 2 + (d - 1) * y) / 2 - d * x0 * x0 - (d - 1) * d * x0 * y - (d - 1) * d * (d * 2 - 1) * y * y;
}

struct query{
    int l, r, id;
};

int32_t main(){
    int n, q; cin >> n >> q;
    for(int i = 0; i < n; i++){
        cin >> a[i];
    }

    vector<query> Q;
    for(int i = 0; i < q; i++){
        int l, r; cin >> l >> r; --l; --r; Q.push_back({l, r, i});
    }
    sort(Q.begin(), Q.end(), [](query a, query b){
        if(a.l / SQ != b.l / SQ) return a.l / SQ < b.l / SQ;
        return a.l / SQ % 2 ? a.r > b.r : a.r < b.r;
    });

    int l = 0, r = -1;
    for(auto [ql, qr, id] : Q){
        while(l > ql) add(a[--l]);
        while(r < qr) add(a[++r]);
        while(l < ql) rem(a[l++]);
        while(r > qr) rem(a[r--]);
        int res = s0 + (s1 * s1 - s2) / 2;
        int cl = 0, cr = 0;
        for(auto y : s){
            if(cl > cr) swap(cl, cr);
            int cnt = cc[y];
            int d = min(cnt, (cr - cl) / y);
            res += f(cl, d, y, s1); cl += d * y; cnt -= d;
            res += f(cl, (cnt + 1) / 2, y, s1);
            res += f(cr, cnt / 2, y, s1);
            cl += ((cnt + 1) / 2) * y, cr += (cnt / 2) * y;
        }
        res += cl * (s1 - cl);
        ans[id] = res;
    }

    for(int i = 0; i < q; i++){
        cout << ans[i] << '\n';
    }
}

Compilation message (stderr)

diversity.cpp: In function 'int32_t main()':
diversity.cpp:63:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   63 |     for(auto [ql, qr, id] : Q){
      |              ^

• Subtask 1: 0 / 4
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 0 / 16
• Subtask 5: 0 / 26
• Subtask 6: 0 / 36