Submission #297751

#	Time	Username	Problem	Language	Result	Execution time	Memory
297751		humbertoyusta	Sorting (IOI15_sorting)	C++14	20 / 100	2 ms	640 KiB

sorting

#include "sorting.h"
#include<bits/stdc++.h>
using namespace std;
#define maxn 600050
#define mod 1000000007
#define ll long long
#define f first
#define s second
#define ii pair<ll,ll>
#define db(x) cerr << #x << ": " << (x) << '\n';

int a[maxn], b[maxn], n, m, id[maxn];
ii bc[maxn], gc[maxn];

bool can(int limit){

    for(int i=0; i<n; i++)
        b[i] = a[i];

    for(int i=0; i<limit; i++)
        swap(b[bc[i].f],b[bc[i].s]);

    for(int i=0; i<n; i++){
        id[b[i]] = i;
    }

    int cnt = 0;
    for(int i=0; i<n; i++){
        if( b[i] != i ){
            cnt++;
            int x = id[i];
            int y = i;
            swap( b[x] , b[y] );
            id[ b[x] ] = x;
            id[ b[y] ] = y;
        }
    }

    return ( cnt <= limit );
}

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {

    n = N;
    for(int i=0; i<n; i++){
        a[i] = S[i];
    }
    m = M;
    for(int i=0; i<m; i++){
        bc[i] = { X[i] , Y[i] };
    }

    int l = 1, r = M - 1;
    while( l < r ){
        int mi = ( l + r ) >> 1;
        if( can(mi) ) r = mi;
            else l = mi + 1;
    }
    if( can(l-1) ) l --;
    if( ! can(l) ) l ++;

    for(int i=0; i<n; i++)
        b[i] = a[i];

    for(int i=0; i<l; i++)
        swap(b[bc[i].f],b[bc[i].s]);

    for(int i=0; i<n; i++){
        id[b[i]] = i;
    }

    int cnt = 0;
    for(int i=0; i<n; i++){
        if( b[i] != i ){
            int x = id[i];
            int y = i;
            P[cnt] = x;
            Q[cnt] = y;
            swap( b[x] , b[y] );
            id[ b[x] ] = x;
            id[ b[y] ] = y;
            cnt++;
        }
    }

	return l;
}

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