Submission #552908

#	Time	Username	Problem	Language	Result	Execution time	Memory
552908		elazarkoren	Sorting (IOI15_sorting)	C++17	74 / 100	1094 ms	8088 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
//#define int ll
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;
typedef vector<bool> vb;

const int MAX_N = 2e5 + 5;

int x[MAX_N], y[MAX_N];
int n;

int cnt;

vi Compute(vi s) {
    for (int i = 0; i < cnt; i++) swap(s[x[i]], s[y[i]]);
    return s;
}

bool Ok(int N, int S[], int m, int X[], int Y[], int p[], int q[]) {
    cnt = m;
    vi s(n);
    for (int i = 0; i < n; i++) s[i] = S[i], x[i] = X[i], y[i] = Y[i];
    vi s2 = Compute(s);
    int index = 0;
    for (int i = 0; i < cnt; i++) {
        swap(s[x[i]], s[y[i]]);
        int v1 = 0, v2 = 0;
        for (; index < n; index++) {
            if (s2[index] == index) continue;
            for (int j = index + 1; j < n; j++) {
                if (s2[j] == index) {
                    v1 = s2[index], v2 = s2[j];
                    swap(s2[index], s2[j]);
                }
            }
            index++;
            break;
        }
        int ind1, ind2;
        for (ind1 = 0; s[ind1] != v1; ind1++);
        for (ind2 = 0; s[ind2] != v2; ind2++);
        p[i] = ind1, q[i] = ind2;
        swap(s[p[i]], s[q[i]]);
    }
    return is_sorted(all(s));
}

int findSwapPairs(int N, int S[], int m, int X[], int Y[], int p[], int q[]) {
    n = N;
    int begin = 0, end = n - 1, mid;
    while (begin < end) {
        mid = (begin + end) >> 1;
        if (Ok(N, S, mid, X, Y, p, q)) {
            end = mid;
        } else begin = mid + 1;
    }
    Ok(N, S, end, X, Y, p, q);
    return end;
}
//8
//3 5 6 2 1 7 0 4
//8
//0 1
//0 1
//0 1
//0 1
//0 1
//0 1
//0 1
//0 1

Compilation message (stderr)

sorting.cpp: In function 'bool Ok(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:29:13: warning: unused parameter 'N' [-Wunused-parameter]
   29 | bool Ok(int N, int S[], int m, int X[], int Y[], int p[], int q[]) {
      |         ~~~~^
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:58:39: warning: unused parameter 'm' [-Wunused-parameter]
   58 | 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