Submission #740615

#	Time	Username	Problem	Language	Result	Execution time	Memory
740615		Olympia	Ekoeko (COCI21_ekoeko)	C++17	110 / 110	87 ms	8648 KiB

Main

#include <iostream>
#include <set>
#include <cmath>
#include <queue>
#include <vector>
#include <cstdlib>
#include <ctime>
#include <cmath>
#include <algorithm>
#include <cassert>
#include <map>
#include <deque>
#include <stdio.h>
using namespace std; 
map<char,vector<int>> pos (string s) {
    map<char,vector<int>> m;
    for (int i = 0; i < s.size(); i++) {
        m[s[i]].push_back(i);
    }
    return m;
}
struct SegmentTree {
    vector<int64_t> vec;
    int64_t query (int dum, int tl, int tr, int l, int r) {
        if (tl >= l and tr <= r) {
            return vec[dum];
        }
        if (r < tl or l > tr) {
            return 0;
        }
        return query(2 * dum + 1, tl, (tl + tr)/2, l, r) + query(2 * dum + 2, (tl + tr)/2 + 1, tr, l, r);
    }
    int64_t query (int l, int r) {
        return query(0, 0, (int)vec.size()/2 - 1, l, r);
    }
    void upd (int x, int y) {
        x += (int)vec.size()/2 - 1;
        vec[x] += y;
        while (x != 0) {
            x = (x - 1)/2;
            vec[x] = vec[2 * x + 1] + vec[2 * x + 2];
        }
    }
    SegmentTree (int n) {
        n = (1 << ((int)log2(n) + 1));
        vec.assign(2 * n, 0);
    }
};
int64_t inversions (vector<int> v) {
    SegmentTree st(v.size());
    int64_t ans = 0;
    for (int i = 0; i < v.size(); i++) {
        st.upd(v[i], 1);
        ans += st.query(v[i] + 1, (int)v.size() - 1);
    }
    return ans;
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    string s;
    cin >> s;
    string str;
    map<int,int> oc_s;
    for (int i = 0; i < s.size(); i++) {
        oc_s[s[i]]++;
    }
    map<char,int> oc;
    string g;
    for (int i = 0; i < s.size(); i++) {
        oc[s[i]]++;
        if (oc[s[i]] <= oc_s[s[i]]/2) {
            str += s[i];
        } else {
            g += s[i];
        }
    }
    auto p1 = pos(s);
    auto p2 = pos(str + str);
    int ans = 0;
    vector<int> perm(2 * n);
    for (auto& p: p1) {
        for (int i = 0; i < p1[p.first].size(); i++) {
            perm[p2[p.first][i]] = p1[p.first][i];
        }
    }
    cout << inversions(perm) << '\n';
}

Compilation message (stderr)

Main.cpp: In function 'std::map<char, std::vector<int> > pos(std::string)':
Main.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     for (int i = 0; i < s.size(); i++) {
      |                     ~~^~~~~~~~~~
Main.cpp: In function 'int64_t inversions(std::vector<int>)':
Main.cpp:52:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for (int i = 0; i < v.size(); i++) {
      |                     ~~^~~~~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:67:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |     for (int i = 0; i < s.size(); i++) {
      |                     ~~^~~~~~~~~~
Main.cpp:72:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     for (int i = 0; i < s.size(); i++) {
      |                     ~~^~~~~~~~~~
Main.cpp:85:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |         for (int i = 0; i < p1[p.first].size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~~~~~~
Main.cpp:82:9: warning: unused variable 'ans' [-Wunused-variable]
   82 |     int ans = 0;
      |         ^~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40