Submission #291569

#	Time	Username	Problem	Language	Result	Execution time	Memory
291569		MarcoMeijer	Sorting (IOI15_sorting)	C++14	74 / 100	1098 ms	8696 KiB

sorting

#include <bits/stdc++.h>

using namespace std;

#include "sorting.h"

//macros
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define INF 1e9
#define pb push_back
#define fi first
#define se second
#define sz size()

const int MX = 2e5+100;

int a[MX], sa[MX], ss[MX];
int b[MX];
int n;
int *S, *X, *Y;

void swapA(int x, int y) {
    swap(a[x], a[y]);
    sa[a[x]] = x;
    sa[a[y]] = y;
}
void swapS(int x, int y) {
    swap(S[x], S[y]);
    ss[S[x]] = x;
    ss[S[y]] = y;
}

int visited[MX];
void dfs(int u) {
    if(visited[u]) return;
    visited[u] = 1;
    dfs(b[u]);
}
bool possible(int swaps) {
    RE(i,n) visited[i] = 0;
    int cyc = 0;
    RE(i,n) {
        if(visited[i]) continue;
        dfs(i);
        cyc++;
    }
    if(n-cyc <= swaps) return 1;
    return 0;
}

int findSwapPairs(int _n, int _S[], int m, int _X[], int _Y[], int P[], int Q[]) {
    n=_n, S=_S, X=_X, Y=_Y;

    RE(i,n) a[i]=sa[i]=i;
    RE(i,n) b[i] = S[i];
    RE(i,n) ss[S[i]] = i;

    int times = 0;
    RE(i,n) {
        if(possible(i)) break;
        swapA(sa[X[i]], sa[Y[i]]);
        swap(b[X[i]], b[Y[i]]);
        times++;
    }

    int R = 0; int curI = 0;
    RE(i,times) {
        R++;
        swapA(X[i], Y[i]);
        swapS(X[i], Y[i]);

        int x=0, y=0;
        while(x == y) {
            if(curI == n) break;    
            x = ss[curI];
            y = sa[curI];
            curI++;
        }

        swapS(x, y);

        P[R-1] = x;
        Q[R-1] = y;
    }
    return R;
}

Compilation message (stderr)

sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:64:41: warning: unused parameter 'm' [-Wunused-parameter]
   64 | 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: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 20 / 20
• Subtask 6: 0 / 26