Submission #712391

#	Time	Username	Problem	Language	Result	Execution time	Memory
712391		Nhoksocqt1	Sorting (IOI15_sorting)	C++17	0 / 100	8 ms	2260 KiB

sorting

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

#define inf 0x3f3f3f3f
#define sz(x) int((x).size())
#define fi first
#define se second
#define round asfhuqfuqwhuqwer
typedef long long ll;
typedef pair<int, int> ii;

template<class X, class Y>
	inline bool maximize(X &x, const Y &y) {return (x < y ? x = y, 1 : 0);}
template<class X, class Y>
	inline bool minimize(X &x, const Y &y) {return (x > y ? x = y, 1 : 0);}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int Random(int l, int r) {
    return uniform_int_distribution<int>(l, r)(rng);
}

const int MAXN = 200005;

ii round[MAXN];
int val[MAXN], P[6 * MAXN][21], Pn[6 * MAXN][21], firstPn[MAXN];
int lastIdx[MAXN], pos[MAXN], tmp[MAXN], nArr, numRound;

#ifdef Nhoksocqt1

int findSwapPairs(int _N, int _S[], int _M, int _X[], int _Y[], int _P[], int _Q[]);
int _S[MAXN], _X[MAXN], _Y[MAXN], _P[MAXN], _Q[MAXN];

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    freopen("SORTING.inp", "r", stdin);
    freopen("SORTING.out", "w", stdout);

    int _N, _M;
    cin >> _N;
    for (int i = 0; i < _N; ++i)
        cin >> _S[i];

    cin >> _M;
    for (int i = 0; i < _M; ++i)
        cin >> _X[i];

    for (int i = 0; i < _M; ++i)
        cin >> _Y[i];

    int ans = findSwapPairs(_N, _S, _M, _X, _Y, _P, _Q);
    cout << ans << '\n';
    for (int it = 0; it < ans; ++it)
        cout << _P[it] << ' ' << _Q[it] << '\n';

    return 0;
}

#endif // Nhoksocqt1

inline int getID(int x) {
    return (x > numRound) ? round[x - numRound].fi : round[x].se;
}

bool check(int nr, int _P[], int _Q[]) {
    for (int i = 1; i <= nArr; ++i) {
        tmp[i] = val[i];
        pos[val[i]] = i;
    }

    int cntNow(0);
    for (int i = 1; i <= nArr; ++i) {
        int to(firstPn[i]);
        for (int j = 20; j >= 0; --j) {
            int now(Pn[to][j]);
            if(now <= numRound && now <= cntNow || now > numRound && now - numRound <= cntNow)
                to = now;
        }

        if(to <= numRound && to <= cntNow || to > numRound && to - numRound <= cntNow)
            to = Pn[to][0];

        int f(to);
        for (int j = 20; j >= 0; --j) {
            int now(P[to][j]);
            if(now <= numRound && now <= nr || now > numRound && now - numRound <= nr)
                to = now;
        }

        //cout << nr << ' ' << i << ' ' << firstPn[i] << ' ' << to << ' ' << getID(to) << '\n';
        if(tmp[i] == getID(to))
            continue;

        if(to <= numRound && to <= nr || to > numRound && to - numRound <= nr) {
            ++cntNow;
            swap(pos[tmp[round[cntNow].fi]], pos[tmp[round[cntNow].se]]);
            swap(tmp[round[cntNow].fi], tmp[round[cntNow].se]);
            if(cntNow > nr)
                return false;

            int x(pos[getID(to)]), y(i);
            if(round[cntNow].fi == i) {
                i = round[cntNow].se;
            } else
                if(round[cntNow].se == i) {
                    i = round[cntNow].fi;
                }

            _P[cntNow - 1] = x - 1, _Q[cntNow - 1] = i - 1;
            swap(pos[tmp[x]], pos[tmp[i]]);
            swap(tmp[x], tmp[i]);
        } else {
            ++cntNow;
            swap(pos[tmp[round[cntNow].fi]], pos[tmp[round[cntNow].se]]);
            swap(tmp[round[cntNow].fi], tmp[round[cntNow].se]);
            if(cntNow > nr)
                return false;

            int x(pos[i]), y(i);
            if(round[cntNow].fi == i) {
                i = round[cntNow].se;
            } else
                if(round[cntNow].se == i) {
                    i = round[cntNow].fi;
                }

            _P[cntNow - 1] = x - 1, _Q[cntNow - 1] = i - 1;
            swap(pos[tmp[x]], pos[tmp[i]]);
            swap(tmp[x], tmp[i]);
        }
    }

    for (int i = cntNow; i < nr; ++i)
        _P[i] = _Q[i] = 0;

    return true;
}

int findSwapPairs(int _N, int _S[], int _M, int _X[], int _Y[], int _P[], int _Q[]) {
    nArr = _N, numRound = _M;
    for (int i = 1; i <= nArr; ++i) {
        val[i] = _S[i - 1] + 1;
    }

    for (int i = 1; i <= 2 * numRound; ++i)
        P[i][0] = Pn[i][0] = 2 * numRound + 1;

    for (int i = 1; i <= numRound; ++i) {
        round[i] = {_X[i - 1] + 1, _Y[i - 1] + 1};
        P[lastIdx[round[i].fi]][0] = i;
        P[lastIdx[round[i].se]][0] = i + numRound;
        lastIdx[round[i].se] = i;
        lastIdx[round[i].fi] = i + numRound;
    }

    for (int i = 1; i <= nArr; ++i)
        lastIdx[i] = 0;

    for (int i = 1; i <= numRound; ++i) {
        Pn[lastIdx[round[i].fi]][0] = i;
        Pn[lastIdx[round[i].se]][0] = i + numRound;
        lastIdx[round[i].fi] = i;
        lastIdx[round[i].se] = i + numRound;
        if(!firstPn[round[i].fi])
            firstPn[round[i].fi] = i;

        if(!firstPn[round[i].se])
            firstPn[round[i].se] = i + numRound;
    }

    P[2 * numRound + 1][0] = Pn[2 * numRound + 1][0] = 2 * numRound + 1;
    for (int j = 1; j <= 20; ++j) {
        for (int i = 1; i <= 2 * numRound + 1; ++i) {
            P[i][j] = P[P[i][j - 1]][j - 1];
            Pn[i][j] = Pn[Pn[i][j - 1]][j - 1];
        }
    }

    int l(0), r(numRound - 1), answer(numRound);
    while(l <= r) {
        int mid = (l + r) >> 1;
        if(check(mid, _P, _Q)) {
            answer = mid;
            r = mid - 1;
        } else {
            l = mid + 1;
        }
    }

    check(answer, _P, _Q);
    return answer;
}

Compilation message (stderr)

sorting.cpp: In function 'bool check(int, int*, int*)':
sorting.cpp:77:32: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   77 |             if(now <= numRound && now <= cntNow || now > numRound && now - numRound <= cntNow)
      |                ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
sorting.cpp:81:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   81 |         if(to <= numRound && to <= cntNow || to > numRound && to - numRound <= cntNow)
      |            ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
sorting.cpp:87:32: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   87 |             if(now <= numRound && now <= nr || now > numRound && now - numRound <= nr)
      |                ~~~~~~~~~~~~~~~~^~~~~~~~~~~~
sorting.cpp:95:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   95 |         if(to <= numRound && to <= nr || to > numRound && to - numRound <= nr) {
      |            ~~~~~~~~~~~~~~~^~~~~~~~~~~
sorting.cpp:102:36: warning: unused variable 'y' [-Wunused-variable]
  102 |             int x(pos[getID(to)]), y(i);
      |                                    ^
sorting.cpp:120:28: warning: unused variable 'y' [-Wunused-variable]
  120 |             int x(pos[i]), y(i);
      |                            ^
sorting.cpp:84:13: warning: unused variable 'f' [-Wunused-variable]
   84 |         int f(to);
      |             ^

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