Submission #368112

#	Time	Username	Problem	Language	Result	Execution time	Memory
368112		leinad2	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	179 ms	16108 KiB

shoes

#include "shoes.h"
#include<bits/stdc++.h>
using namespace std;
int seg[800010];
void update(int id, int s, int e, int x, int v)
{
    if(e<x||x<s)return;
    if(s==e)
    {
        seg[id]=v;
        return;
    }
    int m=s+e>>1;
    update(id*2, s, m, x, v);
    update(id*2+1, m+1, e, x, v);
    seg[id]=seg[id*2]+seg[id*2+1];
}
int get(int id, int s, int e, int l, int r)
{
    if(e<l||r<s)return 0;
    if(l<=s&&e<=r)return seg[id];
    int m=s+e>>1;
    return get(id*2, s, m, l, r)+get(id*2+1, m+1, e, l, r);
}
vector<int>v[200010];
long long count_swaps(vector<int>s)
{
    long long ans=0;
    int i, j;
    int n=s.size()/2;
    for(i=0;i<s.size();i++)
    {
        if(s[i]>0)v[s[i]].push_back(i);
        else v[-s[i]+n].push_back(i);
    }
    for(i=0;i++<2*n;)reverse(v[i].begin(), v[i].end());
    for(i=0;i<s.size();i++)
    {
        if(get(1, 1, 2*n, i+1, i+1))continue;
        if(s[i]>0)v[s[i]].pop_back(),ans++;
        else v[-s[i]+n].pop_back();
        if(s[i]>0)
        {
            j=v[s[i]+n].back();
            v[s[i]+n].pop_back();
        }
        else
        {
            j=v[-s[i]].back();
            v[-s[i]].pop_back();
        }
        //printf("%d %d\n", i, j);
        ans+=(j-i-1);
        ans-=get(1, 1, 2*n, i+2, j+1);
        update(1, 1, 2*n, j+1, 1);
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'void update(int, int, int, int, int)':
shoes.cpp:13:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   13 |     int m=s+e>>1;
      |           ~^~
shoes.cpp: In function 'int get(int, int, int, int, int)':
shoes.cpp:22:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   22 |     int m=s+e>>1;
      |           ~^~
shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:31:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for(i=0;i<s.size();i++)
      |             ~^~~~~~~~~
shoes.cpp:37:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     for(i=0;i<s.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