Submission #296604

#	Time	Username	Problem	Language	Result	Execution time	Memory
296604		zoooma13	Arranging Shoes (IOI19_shoes)	C++14	50 / 100	1094 ms	24184 KiB

shoes

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

vector <bool> st;
int qry(int l ,int r){
    int ret = 0;
    for(int i=l; i<=r; i++)
        ret += !st[i];
    return ret;
}

long long count_swaps(vector<int> s) {
    st.resize(s.size());

    map <int ,vector<int>> mp;
    for(int i=(int)s.size()-1; ~i; i--)
        mp[s[i]].push_back(i);

    long long ans = 0;
    for(int i=0; i<s.size(); i++) if(!st[i]){
        int x = s[i]; mp[x].pop_back();
        int y_idx = mp[-x].back(); mp[-x].pop_back();
        st[i] = 1 ,st[y_idx] = 1;
        ans += qry(i+1 ,y_idx-1)+(x > 0);
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:21:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     for(int i=0; i<s.size(); i++) if(!st[i]){
      |                  ~^~~~~~~~~

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