Submission #408827

#	Time	Username	Problem	Language	Result	Execution time	Memory
408827		MDario	Sorting (IOI15_sorting)	C++11	100 / 100	172 ms	22516 KiB

sorting

#include "sorting.h"
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
int n, s[200001], m, x[600001], y[600001];
bool f(ll xf){
    int s1[200001];
    for(int i=0; i<n; i++){
        s1[i]=s[i];
    }
    int c=0;
    for(int i=0; i<xf; i++){
        swap(s1[x[i]], s1[y[i]]);
    }
    for(int i=0; i<n; i++){
        while(s1[i]!=i){
            c++;
            swap(s1[i], s1[s1[i]]);
        }
    }
    return (c<=xf);
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    n=N;
    m=M;
    bool b=1;
    for(int i=0; i<n; i++){
        s[i]=S[i];
        if(S[i]!=i)b=0;
    }
    if(b)return 0;
    for(int i=0; i<n; i++){
        x[i]=X[i];
        y[i]=Y[i];
    }
    int l=0, r=n+1, mid=0;
    while(l+1<r){
        mid=(l+r)/2;
        if(f(mid)){
            r=mid;
        }
        else l=mid;
    }
    int c=0;
    l++;
//    cout << l << "\n";
    int s1[n], p[n];
    for(int i=0; i<n; i++){
        s1[i]=i;
        p[i]=i;
    }
    for(int i=0; i<l; i++){
        swap(S[x[i]], S[y[i]]);
        swap(s1[x[i]], s1[y[i]]);
        swap(p[s1[x[i]]], p[s1[y[i]]]);
    }
    for(int i=0; i<n; i++){
        while(S[i]!=i){
            swap(s1[p[x[c]]], s1[p[y[c]]]);
            swap(p[s1[p[x[c]]]], p[s1[p[y[c]]]]);
            P[c]=s1[i];
            Q[c]=s1[S[i]];
            //cout << P[c] << " " << Q[c] << "\n";
//            for(int t=0; t<n; t++){
//                cout << s1[t] << " ";
//            }
//            cout << "\n";
            c++;
            swap(S[i], S[S[i]]);
        }
    }
    for(int i=c; i<l; i++){
        P[i]=0;
        Q[i]=0;
    }
	return l;
}

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