Submission #599255

#	Time	Username	Problem	Language	Result	Execution time	Memory
599255		daisy2	Arranging Shoes (IOI19_shoes)	C++14	50 / 100	56 ms	15556 KiB

shoes

#include<iostream>
#include<vector>
#include "shoes.h"
using namespace std;
vector<int> v[300005];
const int ma=100005;
int fenwick[100005];
void update(int p,int v)
{
    for(int i=p;i<=100001;i+= i & -i)
    {
        fenwick[i]+=v;
    }
}
long long sum(long long x)
{
    long long r=0;
    for(int i=x;i>0;i -= i & -i)
    {
        r+=fenwick[i];
    }
    return r;
}
bool used[100005];
long long count_swaps(std::vector<int> s) {

    for(int i=s.size()-1;i>=0;i--)
    {
        if(v[ma+s[i]].empty()) v[ma+s[i]].push_back(0);
        v[ma+s[i]].push_back(i);
        v[ma+s[i]][0]++;
        update(i+1,1);
    }
    int in2;
    long long a=0;
    for(int i=0;i<s.size();i++)
    {
        if(used[i]) continue;

        in2=v[ma-s[i]][v[ma-s[i]][0]];v[ma-s[i]][0]--;
        v[ma+s[i]][0]--;
        used[in2]=1;

        a+=sum(in2)-sum(i+1);
        update(in2+1,-1);

        if(s[in2]<s[i]) a++;
    }
	return a;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int i=0;i<s.size();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