Submission #143876

#	Time	Username	Problem	Language	Result	Execution time	Memory
143876		RezwanArefin01	Arranging Shoes (IOI19_shoes)	C++14	45 / 100	353 ms	273312 KiB

shoes

#include <bits/stdc++.h>
#include "shoes.h"

using namespace std; 

const int N = 2e5 + 10; 

deque<int> pos[2][N];
int r[N], bit[N];

void update(int x) { ++x; 
    for(; x > 0; x -= x & -x)
        ++bit[x];
}

int read(int x) { ++x;
    int ret = 0;
    for(; x < N; x += x & -x) 
        ret += bit[x];
    return ret; 
}

long long count_swaps(vector<int> s) {
    vector<int> ord;
    for(int i = 0; i < s.size(); ++i) {
        int x = abs(s[i]), c = s[i] > 0; 
        if(pos[c ^ 1][x].size()) {
            int j = pos[c ^ 1][x].front(); 
            pos[c ^ 1][x].pop_front(); 
            r[j] = i; 
        } else {
            pos[c][x].push_back(i); 
            ord.push_back(i);
        }
    }

    long long ans = 0;
    for(int i : ord) {
        int L = i + read(i); 
        int R = r[i] + read(r[i]);

        ans += R - L - 1; 
        if(s[i] > 0) ++ans;
        update(R);
    }

    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:25:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < s.size(); ++i) {
                    ~~^~~~~~~~~~

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