#include<cstdio>
#include<vector>
#include<map>
#include<utility>
#include<iostream>
#include<algorithm>
#include<list>
using namespace std;
int main(){
//printf("2\n5\n5 6 1 4 3\n4\n1 2 3 4");
//return 0;
int n;
int t;
int x,y;
vector<pair<int, int>> v;
v.push_back({0,0});
scanf("%d", &n);
for(int i=1; i<=n; i++){
scanf("%d", &t);
v.push_back({t, i});
}
sort(v.begin(), v.end());
list<vector<int>> all_cykles;
for(int i = 1; i<=n; i++){
int act;
if(i == v[i].second)
continue;
if(v[i].first == 0)
continue;
v[i].first = 0;
act = v[i].second;
vector<int> cykle = {i};
while( act != i){
v[act].first = 0;
cykle.push_back(act);
act = v[act].second;
}
/*
printf("Cykle :\n");
for (auto r: cykle)
printf("%d ", r);*/
all_cykles.push_front(cykle);
}
if (all_cykles.empty()){
printf("0\n");
return 0;
}
list<int> iter_list = {};
list<int> iter_list2 = {};
for(auto &a: all_cykles){
if(a.size() == 2){
iter_list.push_front(a[0]);
iter_list.push_back(a[1]);
continue;
}
n = a.size();
for(int i=1; i <= (n-1)/2; i++){
iter_list.push_front(a[(n-1)/2-i]);
iter_list.push_back( a[(n-1)/2+i]);
iter_list2.push_front(a[(n-1)/2-i]);
iter_list2.push_back(a[(n-1)/2+i-1]);
}
if (n%2==0){
iter_list2.push_front(a[(n-1)]);
iter_list2.push_back(a[(n-2)]);
}
}
if (iter_list2.empty()){
printf("1\n%ld\n", iter_list.size());
for (auto i: iter_list)
printf("%d ", i);
// printf("\n");
}
else{
printf("2\n%ld\n", iter_list.size());
for (auto i: iter_list)
printf("%d ", i);
printf("\n%ld\n", iter_list2.size());
for (auto i: iter_list2)
printf("%d ", i);
}
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 | #include<cstdio> #include<vector> #include<map> #include<utility> #include<iostream> #include<algorithm> #include<list> using namespace std; int main(){ //printf("2\n5\n5 6 1 4 3\n4\n1 2 3 4"); //return 0; int n; int t; int x,y; vector<pair<int, int>> v; v.push_back({0,0}); scanf("%d", &n); for(int i=1; i<=n; i++){ scanf("%d", &t); v.push_back({t, i}); } sort(v.begin(), v.end()); list<vector<int>> all_cykles; for(int i = 1; i<=n; i++){ int act; if(i == v[i].second) continue; if(v[i].first == 0) continue; v[i].first = 0; act = v[i].second; vector<int> cykle = {i}; while( act != i){ v[act].first = 0; cykle.push_back(act); act = v[act].second; } /* printf("Cykle :\n"); for (auto r: cykle) printf("%d ", r);*/ all_cykles.push_front(cykle); } if (all_cykles.empty()){ printf("0\n"); return 0; } list<int> iter_list = {}; list<int> iter_list2 = {}; for(auto &a: all_cykles){ if(a.size() == 2){ iter_list.push_front(a[0]); iter_list.push_back(a[1]); continue; } n = a.size(); for(int i=1; i <= (n-1)/2; i++){ iter_list.push_front(a[(n-1)/2-i]); iter_list.push_back( a[(n-1)/2+i]); iter_list2.push_front(a[(n-1)/2-i]); iter_list2.push_back(a[(n-1)/2+i-1]); } if (n%2==0){ iter_list2.push_front(a[(n-1)]); iter_list2.push_back(a[(n-2)]); } } if (iter_list2.empty()){ printf("1\n%ld\n", iter_list.size()); for (auto i: iter_list) printf("%d ", i); // printf("\n"); } else{ printf("2\n%ld\n", iter_list.size()); for (auto i: iter_list) printf("%d ", i); printf("\n%ld\n", iter_list2.size()); for (auto i: iter_list2) printf("%d ", i); } } |
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