Submission #296768

#	Time	Username	Problem	Language	Result	Execution time	Memory
296768		peti1234	Sorting (IOI15_sorting)	C++17	20 / 100	2 ms	512 KiB

sorting

#include <bits/stdc++.h>

using namespace std;
const int c=200002;
int lo, hi, mid, st=0, a[c], ia[c], b[c], ib[c], cs1, cs2;
vector<int> e, f;
int findSwapPairs(int n, int s[], int m, int x[], int y[], int p[], int q[]) {
    lo=-1, hi=n;
    //lo=1, hi=3;
    while(hi-lo>1) {
        mid=(hi+lo)/2, st=0;
        for (int i=0; i<n; i++) a[i]=s[i], b[i]=i, ia[s[i]]=i, ib[i]=i;
        e.clear(), f.clear();
        for (int i=mid-1; i>=0; i--) swap(ib[b[x[i]]], ib[b[y[i]]]), swap(b[x[i]], b[y[i]]);
        /*if (mid==1) {
            for (int i=0; i<n; i++) cout << a[i] << " ";
            cout << "\n";
            for (int i=0; i<n; i++) cout << b[i] << " ";
            cout << "\n";
        }*/
        cs1=x[0], cs2=y[0];
        if (mid) {
            swap(ia[a[cs1]], ia[a[cs2]]), swap(a[cs1], a[cs2]);
            swap(ib[b[cs1]], ib[b[cs2]]), swap(b[cs1], b[cs2]);
        }
        for (int i=0; i<n; i++) {
            if (ia[i]!=ib[i]) {
                cs1=ia[i], cs2=ib[i];
                /*if (mid==1) {
                    cout << "csere " << cs1 << " " << cs2 << "\n";
                }*/
                e.push_back(cs1), f.push_back(cs2);
                //p[st]=cs1, q[st]=cs2;
                swap(ia[a[cs1]], ia[a[cs2]]), swap(a[cs1], a[cs2]);
                st++;
                if (st<mid) {
                cs1=x[st], cs2=y[st];
                swap(ia[a[cs1]], ia[a[cs2]]), swap(a[cs1], a[cs2]);
                swap(ib[b[cs1]], ib[b[cs2]]), swap(b[cs1], b[cs2]);
                }
                /*if (mid==1 && st==0) {
                    for (int i=0; i<n; i++) cout << ia[i] << " ";
                    cout << "\n";
                    for (int i=0; i<n; i++) cout << ib[i] << " ";
                    cout << "\n";
                }*/
            }
        }
        //cout << mid << " " << st << endl;
        if (st<=mid) {
            hi=mid;
            for (int i=0; i<mid; i++) p[i]=e[i], q[i]=f[i];
        }
        else lo=mid;
    }
    //for(int i=0; i<hi; i++) cout << p[i] << " " << q[i] << "\n";
    return hi;
}

Compilation message (stderr)

sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:7:39: warning: unused parameter 'm' [-Wunused-parameter]
    7 | int findSwapPairs(int n, int s[], int m, int x[], int y[], int p[], int q[]) {
      |                                   ~~~~^

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