Submission #931973

#	Time	Username	Problem	Language	Result	Execution time	Memory
931973		sysia	Diversity (CEOI21_diversity)	C++17	64 / 100	189 ms	24548 KiB

diversity

//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &x) {cerr << '"' << x << '"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 30;
const int mod = 998244353;

void solve(){
    int n, q; cin >> n >> q;
    vector<int>a(n+1);
    map<int, int>cnt;
    for (int i = 1; i<=n; i++){
        cin >> a[i];
        cnt[a[i]]++;
    }
    vector<int>curr;
    for (auto [aa, b]: cnt){
        curr.emplace_back(b);
    }
    sort(curr.begin(), curr.end());
    int m = (int)curr.size();
    int L = 0, R = m-1;
    vector<int>what(m);
    int ptr = 0;
    while (R >= L){
        what[L++] = curr[ptr++];
        if (R < L) break;
        what[R--] = curr[ptr++];
    }
    
    debug(curr);
    debug(what);
    int ans = 0;
    for (auto x: what) {
        ans += (x*(x+1))/2;
    }
    int s = 0, ilo = 0;
    for (int i = 0; i<m; i++){
        ans += (i+1) * s * what[i];
        ans -= what[i] * ilo;
        s += what[i];
        ilo += i*what[i];
    }
    cout << ans << "\n";
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    //cin >> t;
    while (t--) solve();

    return 0;
}

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