Submission #572151

#	Time	Username	Problem	Language	Result	Execution time	Memory
572151		Hanksburger	Sorting (IOI15_sorting)	C++17	54 / 100	3 ms	468 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
int a[200005], b[200005], c[200005], d[200005];
int findSwapPairs(int n, int s[], int m, int x[], int y[], int p[], int q[])
{
    int l=1, r=m, mid, cur;
    while (l<r)
    {
        mid=(l+r)/2;
        for (int i=0; i<n; i++)
        {
            a[i]=b[i]=i;
            c[i]=s[i];
            d[s[i]]=i;
        }
        for (int i=mid-1; i>=0; i--)
        {
            swap(a[x[i]], a[y[i]]);
            swap(b[a[x[i]]], b[a[y[i]]]);
        }
        cur=0;
        for (int i=0; i<mid; i++)
        {
            swap(a[x[i]], a[y[i]]);
            swap(b[a[x[i]]], b[a[y[i]]]);
            swap(c[x[i]], c[y[i]]);
            swap(d[c[x[i]]], d[c[y[i]]]);
            while (cur<=n && b[cur]==d[cur])
                cur++;
            if (cur<n)
            {
                swap(c[b[cur]], c[d[cur]]);
                swap(d[c[b[cur]]], d[c[d[cur]]]);
                while (cur<=n && b[cur]==d[cur])
                    cur++;
            }
        }
        if (cur<n)
            l=mid+1;
        else
            r=mid;
    }
    for (int i=0; i<n; i++)
    {
        a[i]=b[i]=i;
        c[i]=s[i];
        d[s[i]]=i;
    }
    for (int i=l-1; i>=0; i--)
    {
        swap(a[x[i]], a[y[i]]);
        swap(b[a[x[i]]], b[a[y[i]]]);
    }
    cur=0;
    for (int i=0; i<l; i++)
    {
        swap(a[x[i]], a[y[i]]);
        swap(b[a[x[i]]], b[a[y[i]]]);
        swap(c[x[i]], c[y[i]]);
        swap(d[c[x[i]]], d[c[y[i]]]);
        while (cur<=n && b[cur]==d[cur])
            cur++;
        if (cur<n)
        {
            p[i]=b[cur];
            q[i]=d[cur];
            swap(c[b[cur]], c[d[cur]]);
            swap(d[c[b[cur]]], d[c[d[cur]]]);
            while (cur<=n && b[cur]==d[cur])
                cur++;
        }
        else
            p[i]=q[i]=0;
    }
    return l;
}

• Subtask 1: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 0 / 20
• Subtask 6: 0 / 26