| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 1065805 |
2024-08-19T11:54:16 Z |
anango |
Sorting (IOI15_sorting) |
C++17 |
|
6 ms |
600 KB |
#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;
int n;
vector<vector<int>> getcycledecomposition(vector<int> p) {
vector<int> visited(n,0);
vector<vector<int>> cycles;
for (int i=0; i<n; i++) {
if (!visited[i]) {
visited[i] = 1;
vector<int> cycle={i};
while (p[cycle.back()]!=i) {
visited[p[cycle.back()]] = 1;
cycle.push_back(p[cycle.back()]);
}
cycles.push_back(cycle);
}
}
return cycles;
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
n=N;
vector<int> rev(n); for (int i=0; i<n; i++) rev[i] = i;
vector<int> revpos(n); for (int i=0; i<n; i++) revpos[i] = i;
vector<int> pos(n); for (int i=0; i<n; i++) pos[i] = i;
vector<int> seq(n); for (int i=0; i<n; i++) seq[i] = S[i];
for (int i=0; i<M; i++) {
swap(pos[X[i]],pos[Y[i]]);
}
vector<int> reqperm(n,-1); for (int i=0; i<n; i++) reqperm[i] = seq[pos[i]];
vector<int> reverse_finalpos(n,-1); for (int i=0; i<n; i++) reverse_finalpos[pos[i]] = i;
vector<vector<int>> cycles = getcycledecomposition(reqperm);
vector<pair<int,int>> swaps;
for (auto i:cycles) {
for (int j=1; j<i.size(); j++) {
swaps.push_back({i[0],i[j]});
}
}
reverse(swaps.begin(), swaps.end());
vector<int> state(n); for (int i=0; i<n; i++) state[i] = i; //the current 'pos'
//swaps={{0,3},{0,2}};
while (swaps.size()<M) {
swaps.push_back({0,0});
}
vector<int> revperm(n); for (int i=0; i<n; i++) revperm[S[i]] = i;
vector<int> perm(n); for (int i=0; i<n; i++) perm[i] = S[i];
for (int sw=0; sw<M; sw++) {
swap(revperm[perm[X[sw]]],revperm[perm[Y[sw]]]);
swap(perm[X[sw]],perm[Y[sw]]);
pair<int,int> swp = swaps[sw];
int a = swp.first;
int b = swp.second;
//cout << "trying2 " << a <<" " << b << endl;
a=revperm[a]; b=revperm[b];
//cout << "trying3 " << a <<" " << b << endl;
swap(revperm[perm[a]],revperm[perm[b]]);
swap(perm[a],perm[b]);
P[sw] = a; Q[sw] = b;
//cout << "swapping " << a <<" " << b<<endl;
//cout << "ITERATION " << sw << endl;
for (int i=0; i<n; i++) {
assert(revperm[perm[i]]==i);
}
/*for (int i=0; i<n; i++) {
cout << revperm[i] <<" ";
}
cout << endl;
for (int i=0; i<n; i++) {
cout << perm[i] <<" ";
}
cout << endl;*/
}
/*for (int i=0; i<n; i++) {
cout << pos[i] << " ";
}
cout << endl;
for (int i=0; i<swaps.size(); i++) {
cout << swaps[i].first <<" " << swaps[i].second << endl;
}
cout << endl;
for (int i=0; i<n; i++) {
cout << reqperm[i] << " ";
}
cout << endl;*/
vector<int> cur(n); for (int i=0; i<n; i++) cur[i] = S[i];
for (int i=0; i<M; i++) {
swap(cur[X[i]],cur[Y[i]]);
swap(cur[P[i]],cur[Q[i]]);
}
for (int i=0; i<n; i++) {
assert(cur[i]==i);
}
/*cout << "final result" << endl;
for (int i=0; i<n; i++) {
cout << cur[i] <<" ";
}
cout << endl;*/
return M;
}
Compilation message
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:39:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
39 | for (int j=1; j<i.size(); j++) {
| ~^~~~~~~~~
sorting.cpp:46:24: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
46 | while (swaps.size()<M) {
| ~~~~~~~~~~~~^~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
1 ms |
348 KB |
Output is correct |
| 3 |
Correct |
1 ms |
348 KB |
Output is correct |
| 4 |
Correct |
1 ms |
348 KB |
Output is correct |
| 5 |
Correct |
2 ms |
348 KB |
Output is correct |
| 6 |
Correct |
0 ms |
344 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
344 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 5 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
600 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
6 ms |
600 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
