Submission #1108478

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108478		Tahmid690	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	405 ms	166964 KiB

shoes

#include "shoes.h"
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
 
template <typename T> using o_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T, typename R> using o_map = tree<T, R, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 

long long count_swaps(std::vector<int> s) {
    long long n=s.size()/2;
    vector<long long> dst;
    map<long long,long long> mp;
    queue<long long> Q[2*n+2];
    for(auto u:s){
        if(mp[u]==0){
            dst.push_back(min(u,-u));
            dst.push_back(max(-u,u));
            mp[-u]++;
        }
        else{
            mp[u]--;
        }
    }
    for(long long i=0;i<dst.size();i++){
        Q[dst[i]+n].push(i+1);
    }
 
    vector<long long> inv;
    for(auto u:s){ 
        inv.push_back(Q[u+n].front());
        Q[u+n].pop();
    }
    long long cnt=0;
    o_set<long long> st;
    for(auto u:inv){
        cnt+=st.order_of_key(-u);
        st.insert(-u);
    }
    return cnt;
}


// signed main() {
//     int n;
//     assert(1 == scanf("%d", &n));
//     vector<int> S(2 * n);
//     for (int i = 0; i < 2 * n; i++)
//         assert(1 == scanf("%d", &S[i]));

//     long long result = count_swaps(S);

//     printf("%lld\n", result);
//     return 0;
// }

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:27:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     for(long long i=0;i<dst.size();i++){
      |                       ~^~~~~~~~~~~

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