oj.uz

Submission #989190

# Submission time Handle Problem Language Result Execution time Memory
989190 2024-05-27T17:19:02 Z crafticat Sorting (IOI15_sorting) C++17
36 / 100
 104 ms 1188 KB 
#include <bits/stdc++.h>

using namespace std;
using pii = pair<int,int>;

vector<int> x, y;
vector<int> initPos;
int n;

bool check(vector<pii> test) {
    vector<int> pos = initPos;
    for (int i = 0; i < test.size(); ++i) {
        swap(pos[x[i]],pos[y[i]]);
        swap(pos[test[i].first],pos[test[i].second]);
    }
    for (int i = 0; i < n; ++i) {
        if (pos[i] != i)
            return false;
    }
    return true;
}

vector<pii> solve(int m) {
    vector<int> pos = initPos;
    vector<int> posPoint = initPos;
    vector<int> orgPosTo(n), orgPos(n);
    vector<bool> notSorted(n);
    vector<pii> ans;
    for (int i = 0; i < n; ++i) {
        orgPosTo[i] = i;
    }
    for (int i = 0;i < m;i++) {
        swap(pos[x[i]],pos[y[i]]);
    }
    for (int i = m - 1; i >=0 ; --i) {
        swap(orgPosTo[x[i]],orgPosTo[y[i]]);
    }
    for (int i = 0; i < n; ++i) {
        orgPos[orgPosTo[i]] = i;
    }
    for (int i = 0; i < n; ++i) {
        if (pos[i] != i) notSorted[i] = true;
        posPoint[pos[i]] = i;
    }
    for (int i = 0; i < m; ++i) {
        if (!notSorted[i % n]) continue;
        int j = posPoint[i % n];
        swap(orgPosTo[x[i]],orgPosTo[y[i]]);
        orgPos[orgPosTo[x[i]]] = x[i];
        orgPos[orgPosTo[y[i]]] = y[i];

        int target = pos[j];
        notSorted[target] = false;

        swap(pos[target],pos[j]);
        for (int k = 0; k < n; ++k) {
            posPoint[pos[k]] = k;
        }
        if (pos[j] == j)
            notSorted[j] = false;
        ans.emplace_back(orgPos[j],orgPos[target]);
    }
    for (int i = ans.size(); i < m; ++i) {
        int j = posPoint[(i - ans.size()) % n];
        swap(orgPosTo[x[i]],orgPosTo[y[i]]);
        orgPos[orgPosTo[x[i]]] = x[i];
        orgPos[orgPosTo[y[i]]] = y[i];

        int target = pos[j];
        notSorted[target] = false;

        swap(pos[target],pos[j]);
        for (int k = 0; k < n; ++k) {
            posPoint[pos[k]] = k;
        }
        if (pos[j] == j) notSorted[j] = false;
        ans.emplace_back(orgPos[j],orgPos[target]);
    }
    for (int i = 0; i < n; ++i) {
        if (notSorted[i]) return {};
    }
    if (!check(ans))
        return {};
    return ans;
}

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    n = N;
    x.resize(M);
    y.resize(M);
    initPos.resize(n);

    for (int i = 0; i < M; ++i) {
        x[i] = X[i];
    }
    for (int i = 0; i < M; ++i) {
        y[i] = Y[i];
    }
    for (int i = 0; i < n; ++i) {
        initPos[i] = S[i];
    }

    bool stopIm = true;
    for (int i = 0; i < n; ++i) {
        if (initPos[i] != i) stopIm = false;
    }
    if (stopIm) return {};

    int l = 0, r = M;
    while (l < r) {
        int mid = l + (r - l) / 2;
        if (solve(mid).empty()) {
            l = mid + 1;
        } else
            r = mid;
    }

    auto v = solve(l);
    if (!v.empty()) {
        for (int j = 0; j < v.size(); ++j) {
            P[j] = v[j].first;
        }
        for (int j = 0; j < v.size(); ++j) {
            Q[j] = v[j].second;
        }
        return v.size();
    }
}

#if DEBUG
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 x; cin >> x;
    return x;
}


int main()
{
	_inputFile = fopen("sorting.in", "rb");
	_outputFile = fopen("sorting.out", "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);
	cout << ans << endl;
	for (int i = 0; i < ans; ++i)
		cout << P[i] << " " << Q[i] << endl;
	return 0;
}
#endif

Compilation message

sorting.cpp: In function 'bool check(std::vector<std::pair<int, int> >)':
sorting.cpp:12:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |     for (int i = 0; i < test.size(); ++i) {
      |                     ~~^~~~~~~~~~~~~
sorting.cpp: In function 'std::vector<std::pair<int, int> > solve(int)':
sorting.cpp:63:26: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   63 |     for (int i = ans.size(); i < m; ++i) {
      |                  ~~~~~~~~^~
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:120:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |         for (int j = 0; j < v.size(); ++j) {
      |                         ~~^~~~~~~~~~
sorting.cpp:123:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |         for (int j = 0; j < v.size(); ++j) {
      |                         ~~^~~~~~~~~~
sorting.cpp:126:22: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  126 |         return v.size();
      |                ~~~~~~^~
sorting.cpp:118:21: warning: control reaches end of non-void function [-Wreturn-type]
  118 |     auto v = solve(l);
      |                     ^

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 344 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 344 KB Output is correct
11 Correct 1 ms 344 KB Output is correct
12 Correct 1 ms 348 KB Output is correct

Subtask #3
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 344 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 344 KB Output is correct

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 344 KB Output is correct
11 Correct 1 ms 344 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 344 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 1 ms 344 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 344 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 47 ms 776 KB Output is correct
22 Correct 93 ms 928 KB Output is correct
23 Correct 104 ms 920 KB Output is correct
24 Runtime error 88 ms 1188 KB Execution killed with signal 6
25 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Runtime error 90 ms 848 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #6
0 / 26.0

# Verdict Execution time Memory Grader output
1 Runtime error 90 ms 848 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -