Submission #556575

#	Time	Username	Problem	Language	Result	Execution time	Memory
556575		eecs	Izbori (COCI22_izbori)	C++17	110 / 110	848 ms	14420 KiB

Main

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

const int maxn = 200010;
int n, a[maxn], sum[maxn], c[maxn * 2];
long long ans;
map<int, vector<int>> mp;

void add(int p) {
    for (p += maxn; p < maxn * 2; p += p & -p) c[p]++;
}

int query(int p) {
    int s = 0;
    for (p += maxn; p; p -= p & -p) s += c[p];
    return s;
}

int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]), mp[a[i]].push_back(i);
    }
    auto calc = [&](int x, int y, int lim) {
        int t = min(x, max(0, y - lim));
        return (2LL * lim + t + 1) * t / 2 + 1LL * (x - t) * y;
    };
    for (auto &p : mp) {
        auto &pos = p.second;
        if (pos.size() <= 1000) {
            for (int i = 0; i < pos.size(); i++) {
                for (int j = i; j < pos.size(); j++) {
                    int l = (i ? pos[i - 1] : 0) + 1;
                    int r = (j + 1 < pos.size() ? pos[j + 1] : n + 1) - 1;
                    int lim = 2 * (j - i);
                    ans += calc(pos[i], r, lim) + calc(l - 1, pos[j] - 1, lim);
                    ans -= calc(l - 1, r, lim) + calc(pos[i], pos[j] - 1, lim);
                }
            }
        } else {
            memset(sum, -1, sizeof(sum));
            for (int x : pos) {
                sum[x] = 1;
            }
            for (int i = 1; i <= n; i++) {
                sum[i] += sum[i - 1];
            }
            memset(c, 0, sizeof(c));
            for (int i = 1; i <= n; i++) {
                add(sum[i - 1]), ans += query(sum[i] - 1);
            }
        }
    }
    printf("%lld\n", ans);
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:31:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |             for (int i = 0; i < pos.size(); i++) {
      |                             ~~^~~~~~~~~~~~
Main.cpp:32:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |                 for (int j = i; j < pos.size(); j++) {
      |                                 ~~^~~~~~~~~~~~
Main.cpp:34:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |                     int r = (j + 1 < pos.size() ? pos[j + 1] : n + 1) - 1;
      |                              ~~~~~~^~~~~~~~~~~~
Main.cpp:20:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
Main.cpp:22:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |         scanf("%d", &a[i]), mp[a[i]].push_back(i);
      |         ~~~~~^~~~~~~~~~~~~

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