Submission #482555

#	Time	Username	Problem	Language	Result	Execution time	Memory
482555		PiejanVDC	Sorting (IOI15_sorting)	C++17	0 / 100	2 ms	460 KiB

sorting

#include <bits/stdc++.h>
#include "sorting.h"
using namespace std;

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    priority_queue<pair<int,int>>pq;
    int n = N;
    vector<int>cnt(N,0);
    for(int i = 0 ; i < N ; i++) {
        cnt[X[i]]++,cnt[Y[i]]++;
    }
    vector<int>pos(n),need(n);
    for(int i = 0 ; i < n ; i++) {
        pq.push({-cnt[i],i});
        pos[S[i]] = i;
        need[i] = S[i];
    }
    int d=0;
    auto done = [&] (void) -> bool {
        for(int i = 0 ; i < n ; i++)
            if(S[i] != i) return false;
        return true;
    };
    for(int i = 0 ; i < n ; i++) {
        if(done()) return d;
        swap(S[X[i]],S[Y[i]]);
        cnt[X[i]]--,cnt[Y[i]]--;
        swap(pos[S[X[i]]],pos[S[Y[i]]]);
        swap(need[X[i]],need[Y[i]]);
        pq.push({-cnt[X[i]],X[i]});
        pq.push({-cnt[Y[i]],Y[i]});
        while(pq.top().first != -cnt[pq.top().second])
            pq.pop();
        if(pos[pq.top().second] != pq.top().second)
            P[d++] = (min(pos[pq.top().second],pq.top().second)),Q[d] = (max(pos[pq.top().second],pq.top().second)),
            swap(pos[pq.top().second],pos[need[pq.top().second]]), swap(need[pq.top().second],need[pos[pq.top().second]]);
        pq.pop();
    }
    return d;
}
/*
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
//#include "sorting.h"

static char _buffer[1024];
static int _currentChar = 0;
static int _charsNumber = 0;
static FILE *_inputFile, *_outputFile;

static inline int _read() {
    if (_charsNumber < 0) {
        exit(1);
    }
    if (!_charsNumber || _currentChar == _charsNumber) {
        _charsNumber = (int)fread(_buffer, sizeof(_buffer[0]), sizeof(_buffer), _inputFile);
        _currentChar = 0;
    }
    if (_charsNumber <= 0) {
        return -1;
    }
    return _buffer[_currentChar++];
}

static inline int _readInt() {
    int c, x, s;
    c = _read();
    while (c <= 32) c = _read();
    x = 0;
    s = 1;
    if (c == '-') {
        s = -1;
        c = _read();
    }
    while (c > 32) {
        x *= 10;
        x += c - '0';
        c = _read();
    }
    if (s < 0) x = -x;
    return x;
}


int main()
{
	_inputFile = fopen("sorting1.in", "r");
	_outputFile = fopen("sorting1_out.txt", "w");
	int N, M;
	N = _readInt();
	int *S = (int*)malloc(sizeof(int) * (unsigned int)N);
	for (int i = 0; i < N; ++i)
		S[i] = _readInt();
	M = _readInt();
	int *X = (int*)malloc(sizeof(int) * (unsigned int)M), *Y = (int*)malloc(sizeof(int) * (unsigned int)M);
	for (int i = 0; i < M; ++i) {
	    X[i] = _readInt();
	    Y[i] = _readInt();
	}
	int *P = (int*)malloc(sizeof(int) * (unsigned int)M), *Q = (int*)malloc(sizeof(int) * (unsigned int)M);
	int ans = findSwapPairs(N, S, M, X, Y, P, Q);
	fprintf(_outputFile, "%d\n", ans);
	for (int i = 0; i < ans; ++i)
		fprintf(_outputFile, "%d %d\n", P[i], Q[i]);
	return 0;
}

*/

Compilation message (stderr)

sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:5:39: warning: unused parameter 'M' [-Wunused-parameter]
    5 | int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
      |                                   ~~~~^

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