// clang-format off
#include <bits/stdc++.h>
using i64 = int64_t;
namespace space {
template <typename T> bool setmax(T &v, const T a) {
if (v < a) {
v = a;
return true;
} else {
return false;
}
}
template <typename T> bool setmin(T &v, const T a) {
if (v > a) {
v = a;
return true;
} else {
return false;
}
}
int N, M;
std::vector<int> S, X, Y, P, Q;
std::vector<int> RS;
void swap(const int a, const int b) {
P.push_back(a);
Q.push_back(b);
std::swap(S[a], S[b]);
}
int solve() {
int best = M;
for (int step = 0; step <= M; ++step) {
std::vector<int> w(N);
std::iota(w.begin(), w.end(), 0);
for (int i = 0; i < step; ++i)
std::swap(w[X[i]], w[Y[i]]);
auto s = S;
for (int i = 0; i < N; ++i) {
s[S[w[i]]] = i;
}
// sort s
int sum = 0;
for (int i = 0; i < N; ++i) {
if (s[i] == i) continue;
if (s[s[i]] == i and i < s[i]) continue;
++sum;
}
if (sum <= step) setmin(best, step);
}
const int step = best;
std::vector<std::pair<int, int>> swaps;
std::vector<int> w(N);
std::iota(w.begin(), w.end(), 0);
for (int i = 0; i < step; ++i)
std::swap(w[X[i]], w[Y[i]]);
auto s = S;
for (int i = 0; i < N; ++i) {
s[S[w[i]]] = i;
}
std::vector<int> rs(N);
for (int i = 0; i < N; ++i)
rs[s[i]] = i;
int sum = 0;
for (int i = 0; i < N; ++i) {
if (s[i] == i) continue;
if (s[s[i]] == i and i < s[i]) continue;
swaps.push_back({i, s[i]});
++sum;
}
for (int i = 0; i < (int)swaps.size(); ++i) {
P.push_back(rs[swaps[i].first]);
Q.push_back(rs[swaps[i].second]);
std::swap(s[X[step - i - 1]], s[Y[step - i - 1]]);
std::swap(rs[s[X[step - i - 1]]], rs[s[Y[step - i - 1]]]);
}
while ((int)P.size() < step) {
P.push_back(0);
Q.push_back(0);
}
std::reverse(P.begin(), P.end());
std::reverse(Q.begin(), Q.end());
return step;
}
int mfindSwapSpace(int n, int s[], int m, int x[], int y[], int rp[], int rq[]) {
N = n;
M = m;
S.resize(N);
X.resize(M);
Y.resize(M);
RS.resize(N);
for (int i = 0; i < N; ++i) {
S[i] = s[i];
RS[S[i]] = i;
}
for (int i = 0; i < M; ++i) {
X[i] = x[i];
Y[i] = y[i];
}
int R = solve();
for (int i = 0; i < R; ++i) {
std::swap(S[X[i]], S[Y[i]]);
std::swap(S[P[i]], S[Q[i]]);
bool is_sorted = true;
for (int j = 0; j < N; ++j) if (S[i] != j) is_sorted = false;
if (is_sorted) {
R = i + 1;
P.erase(P.begin() + i + 1, P.end());
Q.erase(Q.begin() + i + 1, Q.end());
break;
}
}
for (int i = 0; i < R; ++i) {
rp[i] = P[i];
rq[i] = Q[i];
}
return R;
}
} // namespace space
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
return space::mfindSwapSpace(N, S, M, X, Y, P, Q);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
102 ms |
392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
102 ms |
392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |