/*
Observation:
if we can do it in N turns, we can do it in N + 1
*/
#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define pb push_back
#define ar array
#define all(x) x.begin(), x.end()
#define siz(x) (int)x.size()
#define FOR(x, y, z) for(int x = (y); x < (z); x++)
#define ROF(x, z, y) for(int x = (y-1); x >= (z); x--)
#define F0R(x, z) FOR(x, 0, z)
#define R0F(x, z) ROF(x, 0, z)
#define trav(x, y) for(auto&x:y)
using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using pii = pair<int, int>;
using vpii = vector<pair<int, int>>;
template<class T> inline bool ckmin(T&a, T b) {return b < a ? a = b, 1 : 0;}
template<class T> inline bool ckmax(T&a, T b) {return b > a ? a = b, 1 : 0;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const char nl = '\n';
const int mxN = 2e5 + 10;
const int MOD = 1e9 + 7;
const long long infLL = 1e18;
int findSwapPairs(int n, int* s, int M, int* x, int *y, int *p, int *q){
int l = 0, r = M + 1;
vpii ans;
while(l < r){
int m = l + r; m = (m - (m&1)) / 2;
vi pos(n);
vi cur(n);
vpii ops;
F0R(i, n){
cur[i] = s[i];
}
F0R(i, m){
swap(cur[x[i]], cur[y[i]]);
}
F0R(i, n){
pos[cur[i]] = i;
}
F0R(i, n){
if(cur[i] != i){
int x = cur[i];
// whats currently at the spot we want
int z = pos[i];
// the pos of our current element
ops.pb({i, pos[i]});
cur[z] = x;
cur[i] = i;
pos[i] = i;
pos[x] = z;
}
}
if(siz(ops) <= m){
ans = ops;
r = m;
}
else{
l = m + 1;
}
}
F0R(i, l){
if(i < ans.size()){
p[i] = ans[i].f; q[i] = ans[i].s;
}
else{
p[i] = 0; q[i] = 0;
}
}
return l;
}
//int32_t main(){
// ios_base::sync_with_stdio(0); cin.tie(0);
// int N;
// cin >> N;
// int S[N];
// F0R(i, N){
// cin >> S[i];
// }
// int M;
// cin >> M;
// int X[M], Y[M];
// F0R(i, M){
// cin >> X[i] >> Y[i];
// }
// int P[M], Q[M];
// int res = findSwapPairs(N, S, M, X, Y, P, Q);
// cout << res << nl;
// F0R(i, res){
// cout << P[i] << ' ' << Q[i] << nl;
// }
// return 0;
//}
Compilation message
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:57:21: warning: declaration of 'int x' shadows a parameter [-Wshadow]
57 | int x = cur[i];
| ^
sorting.cpp:38:46: note: shadowed declaration is here
38 | int findSwapPairs(int n, int* s, int M, int* x, int *y, int *p, int *q){
| ~~~~~^
sorting.cpp:77:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
77 | if(i < ans.size()){
| ~~^~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
256 KB |
Output is correct |
2 |
Correct |
1 ms |
256 KB |
Output is correct |
3 |
Correct |
1 ms |
256 KB |
Output is correct |
4 |
Correct |
0 ms |
256 KB |
Output is correct |
5 |
Correct |
0 ms |
256 KB |
Output is correct |
6 |
Correct |
1 ms |
256 KB |
Output is correct |
7 |
Correct |
0 ms |
256 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
256 KB |
Output is correct |
2 |
Correct |
1 ms |
256 KB |
Output is correct |
3 |
Correct |
1 ms |
256 KB |
Output is correct |
4 |
Correct |
0 ms |
256 KB |
Output is correct |
5 |
Correct |
0 ms |
256 KB |
Output is correct |
6 |
Correct |
1 ms |
256 KB |
Output is correct |
7 |
Correct |
0 ms |
256 KB |
Output is correct |
8 |
Correct |
0 ms |
256 KB |
Output is correct |
9 |
Correct |
1 ms |
384 KB |
Output is correct |
10 |
Correct |
1 ms |
384 KB |
Output is correct |
11 |
Correct |
1 ms |
384 KB |
Output is correct |
12 |
Correct |
1 ms |
384 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
256 KB |
Output is correct |
2 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
256 KB |
Output is correct |
2 |
Correct |
1 ms |
256 KB |
Output is correct |
3 |
Correct |
1 ms |
256 KB |
Output is correct |
4 |
Correct |
0 ms |
256 KB |
Output is correct |
5 |
Correct |
0 ms |
256 KB |
Output is correct |
6 |
Correct |
1 ms |
256 KB |
Output is correct |
7 |
Correct |
0 ms |
256 KB |
Output is correct |
8 |
Correct |
0 ms |
256 KB |
Output is correct |
9 |
Correct |
1 ms |
384 KB |
Output is correct |
10 |
Correct |
1 ms |
384 KB |
Output is correct |
11 |
Correct |
1 ms |
384 KB |
Output is correct |
12 |
Correct |
1 ms |
384 KB |
Output is correct |
13 |
Correct |
1 ms |
256 KB |
Output is correct |
14 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
512 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
2 ms |
512 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |