#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;
++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, y;
if(to <= numRound && to <= nr || to > numRound && to - numRound <= nr) {
x = pos[getID(to)], y = i;
} else {
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;
bool check0(1);
for (int i = 1; i <= nArr; ++i) {
val[i] = _S[i - 1] + 1;
check0 &= (val[i] == i);
}
if(check0)
return 0;
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];
}
}
for (int i = 1; i <= numRound; ++i) {
if(check(i, _P, _Q))
return i;
}
return 0;
}
Compilation message
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:102:27: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
102 | if(to <= numRound && to <= nr || to > numRound && to - numRound <= nr) {
| ~~~~~~~~~~~~~~~^~~~~~~~~~~
sorting.cpp:84:13: warning: unused variable 'f' [-Wunused-variable]
84 | int f(to);
| ^
sorting.cpp:101:16: warning: variable 'y' set but not used [-Wunused-but-set-variable]
101 | int x, y;
| ^
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
279 ms |
2260 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
279 ms |
2260 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |