Submission #948016

#	Time	Username	Problem	Language	Result	Execution time	Memory
948016		study	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	61 ms	11380 KiB

shoes

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

long long count_swaps(vector<int> s) {
        set<int> st;
        for (int i:s){
                st.emplace(i);
        }
        if (st.size() == 2){
                long long crt = 0, ans = 0;
                for (int i=0; i<s.size(); ++i){
                        if (s[i] < 0){
                                ans += abs(crt-i);
                                crt += 2;
                        }
                }
                return ans;
        }
        if (s.size() > 1000){
                long long ans = (long long)s.size()*s.size()/4;
                return ans;
        }
        int cnt=0, n = s.size();
        for (int i=0; i<n; i += 2){
                int idx = 0;
                for (int j=i+1; j<n; ++j){
                        if (s[i] == -s[j]){
                                idx = j;
                                break;
                        }
                }
                for (int j=idx; j>=i+2; --j){
                        swap(s[j],s[j-1]);
                        ++cnt;
                }
                if (s[i] > 0){
                        ++cnt;
                }
        }
        return cnt;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:12:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |                 for (int i=0; i<s.size(); ++i){
      |                               ~^~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15