Submission #1041990

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041990		c2zi6	Sorting (IOI15_sorting)	C++14	74 / 100	1064 ms	12120 KiB

sorting

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<typename T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "sorting.h"

#define ANSWER {\
        rep(i, ans.size()) {\
            P[i] = ans[i].ff;\
            Q[i] = ans[i].ss;\
        }\
        return ans.size();\
    }

struct PERM {
    int n;
    VI a;
    VI ind;
    PERM(int N_ARG) : n(N_ARG) {
        a = ind = VI(n);
        rep(i, n) a[i] = ind[i] = i;
    }
    PERM(VI A_ARG) : a(A_ARG) {
        n = a.size();
        ind = VI(n);
        rep(i, n) ind[a[i]] = i;
    }
    int size() {
        return n;
    }
    int& operator[](const int i) {
        return a[i];
    }
};

PERM operator*(const PERM& perm, const PII p) {
    auto[x, y] = p;
    PERM ret = perm;
    swap(ret.ind[ret[x]], ret.ind[ret[y]]);
    swap(ret[x], ret[y]);
    return ret;
}
void operator*=(PERM& perm, const PII p) {
    auto[x, y] = p;
    swap(perm.ind[perm[x]], perm.ind[perm[y]]);
    swap(perm[x], perm[y]);
}

VPI ret;
bool f(const VI& A_ARG, const VPI& op) {
    PERM a(A_ARG);
    int n = a.size();
    int m = op.size();
    PERM cur(n);
    reprl(i, m-1, 0) cur *= op[i];
    int i = 0;
    for (const PII& p : op) {
        cur *= p;
        a *= p;
        while (i < n && a.ind[i] == cur.ind[i]) i++;
        int x, y;
        if (i == n) {
            x = y = 0;
        } else {
            x = a.ind[i];
            y = cur.ind[i];
        }
        ret.pb({x, y});
        a *= mkp(x, y);
    }
    rep(i, n) if (a[i] != i) return false;
    return true;
}

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    int n = N;
    int m = min(M, N);
    VI a(n);
    rep(i, n) a[i] = S[i];
    VPI op(m);
    rep(i, m) op[i] = mkp(X[i], Y[i]);

    VPI ans(m+1);

    VPI curop;
    rep(i, m+1) {
        /*cout << "KPORDZENQ " << i << " HATOV" << endl;*/
        ret.clear();
        if (f(a, curop)) {
            if (ret.size() < ans.size()) {
                ans = ret;
                /*cout << "AVELI LAV PATASXAN GTAV" << endl;*/
                /*rep(i, ans.size()) {*/
                /*    cout << ans[i].ff << " " << ans[i].ss << endl;*/
                /*}*/
            }
        }
        if (i == m) break;
        curop.pb(op[i]);
    }
    ANSWER;
}

Compilation message (stderr)

sorting.cpp: In constructor 'PERM::PERM(VI)':
sorting.cpp:51:19: warning: conversion from 'std::vector<int>::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   51 |         n = a.size();
      |             ~~~~~~^~
sorting.cpp: In function 'PERM operator*(const PERM&, PII)':
sorting.cpp:64:9: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   64 |     auto[x, y] = p;
      |         ^
sorting.cpp: In function 'void operator*=(PERM&, PII)':
sorting.cpp:71:9: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   71 |     auto[x, y] = p;
      |         ^
sorting.cpp: In function 'bool f(const VI&, const VPI&)':
sorting.cpp:80:20: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   80 |     int m = op.size();
      |             ~~~~~~~^~
sorting.cpp:98:9: warning: declaration of 'i' shadows a previous local [-Wshadow]
   98 |     rep(i, n) if (a[i] != i) return false;
      |         ^
sorting.cpp:9:28: note: in definition of macro 'rep'
    9 | #define rep(i, n) for (int i = 0; i < int(n); ++i)
      |                            ^
sorting.cpp:83:9: note: shadowed declaration is here
   83 |     int i = 0;
      |         ^
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:39:24: warning: conversion from 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   39 |         return ans.size();\
      |                ~~~~~~~~^~
sorting.cpp:128:5: note: in expansion of macro 'ANSWER'
  128 |     ANSWER;
      |     ^~~~~~

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