Submission #1124730

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124730		codexistent	Sorting (IOI15_sorting)	C++20	0 / 100	4 ms	5188 KiB

sorting

// #include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long 
#define MAXN 200005
#define FOR(i, a, b) for(ll i = a; i <= b; i++)

vector<pair<ll, ll>> v[MAXN];
ll cv[MAXN], s[MAXN], x[MAXN], y[MAXN], nx[MAXN];
bool d[MAXN];

bool valid(int N, ll m){
    FOR(i, 0, N - 1) cv[i] = i;
    FOR(i, 1, m) swap(cv[x[i]], cv[y[i]]);
    FOR(i, 0, N - 1) nx[cv[i]] = i;

    ll r = 0;
    FOR(i, 0, N - 1) d[i] = s[cv[i]] == i;
    FOR(st, 0, N - 1) if(!d[st]){
        ll lpsz = 0, i = st;
        do{
            d[i] = true;
            i = nx[s[i]];
        }while(i != st);
        r += lpsz - 1;
    }

    return r <= m;
}

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    FOR(i, 0, N - 1) s[i] = S[i];
    FOR(i, 0, M - 1) x[i] = X[i], y[i] = Y[i];

    ll lo = 0, hi = M;
    while(lo < hi){
        ll md = (lo + hi) / 2;
        if(valid(N, md)){
            hi = md;
        }else{
            lo = md + 1;
        }
    }

    
    ll itr = 0;
    FOR(i, 0, N - 1) cv[i] = i;
    FOR(i, 1, lo) swap(cv[x[i]], cv[y[i]]);
    FOR(i, 0, N - 1) nx[cv[i]] = i;

    FOR(i, 0, N - 1) d[i] = s[cv[i]] == i;
    FOR(st, 0, N - 1) if(!d[st]){
        ll i = st;
        do{
            d[i] = true;
            i = nx[s[i]];
            P[itr] = i, Q[itr] = nx[s[i]];
            itr++;
        }while(i != st);
    }

	return lo;
}

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