#include <iostream> #include <algorithm> #include <deque> using namespace std; int pop[3007]; int nast[3007]; int scale[3007]; bool vis[3007]; int n; void swap_elems(int a, int b, deque<int>& move) { move.push_front(a + 1); move.push_back(b + 1); swap(pop[a], pop[b]); nast[pop[a]] = a; nast[pop[b]] = b; // cout << "swap " << a << " " << b << "\n"; // for (int i = 0; i < n; i++) { // cout << pop[i] << " "; // } // cout << "\n"; // for (int i = 0; i < n; i++) { // cout << nast[i] << " "; // } // cout << "\n"; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cin>>n; for (int i = 0; i < n; i++) { cin>>pop[i]; scale[i] = pop[i]; } sort(scale, scale + n); for (int i = 0; i < n; i++) { pop[i] = (int)(lower_bound(scale, scale + n, pop[i]) - scale); // cout << pop[i] + 1 << " "; nast[pop[i]] = i; } // cout << "\n"; deque<int> first; deque<int> second; for (int i = 0; i < n; i++) { if (vis[i] == 0) { int v = i; int len = 0; while (vis[v] == false) { vis[v] = true; len++; v = nast[v]; } if (len == 1) { // OK } else if (len == 2) { swap_elems(i, nast[i], first); } else { int a = i; int b = nast[nast[i]]; swap_elems(a, b, first); while (true) { a = pop[b]; b = nast[b]; if (a == b) break; swap_elems(a, b, first); } } } } for (int i = 0; i < n; i++) vis[i] = false; for (int i = 0; i < n; i++) { if (vis[i] == 0) { int v = i; int len = 0; while (vis[v] == false) { vis[v] = true; len++; v = nast[v]; } if (len == 1) { // OK } else if (len == 2) { swap_elems(i, nast[i], second); } else { int a = i; int b = nast[nast[i]]; swap_elems(a, b, second); while (true) { a = pop[b]; b = nast[b]; if (a == b) break; swap_elems(a, b, second); } } } } if (first.empty()) { cout << 0 << "\n"; } else if (second.empty()) { cout << 1 << "\n"; cout << first.size() << "\n"; while (!first.empty()) { cout << first.front() << " "; first.pop_front(); } } else { cout << 2 << "\n"; cout << first.size() << "\n"; while (!first.empty()) { cout << first.front() << " "; first.pop_front(); } cout << "\n"; cout << second.size() << "\n"; while (!second.empty()) { cout << second.front() << " "; second.pop_front(); } } }
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 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | #include <iostream> #include <algorithm> #include <deque> using namespace std; int pop[3007]; int nast[3007]; int scale[3007]; bool vis[3007]; int n; void swap_elems(int a, int b, deque<int>& move) { move.push_front(a + 1); move.push_back(b + 1); swap(pop[a], pop[b]); nast[pop[a]] = a; nast[pop[b]] = b; // cout << "swap " << a << " " << b << "\n"; // for (int i = 0; i < n; i++) { // cout << pop[i] << " "; // } // cout << "\n"; // for (int i = 0; i < n; i++) { // cout << nast[i] << " "; // } // cout << "\n"; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); cin>>n; for (int i = 0; i < n; i++) { cin>>pop[i]; scale[i] = pop[i]; } sort(scale, scale + n); for (int i = 0; i < n; i++) { pop[i] = (int)(lower_bound(scale, scale + n, pop[i]) - scale); // cout << pop[i] + 1 << " "; nast[pop[i]] = i; } // cout << "\n"; deque<int> first; deque<int> second; for (int i = 0; i < n; i++) { if (vis[i] == 0) { int v = i; int len = 0; while (vis[v] == false) { vis[v] = true; len++; v = nast[v]; } if (len == 1) { // OK } else if (len == 2) { swap_elems(i, nast[i], first); } else { int a = i; int b = nast[nast[i]]; swap_elems(a, b, first); while (true) { a = pop[b]; b = nast[b]; if (a == b) break; swap_elems(a, b, first); } } } } for (int i = 0; i < n; i++) vis[i] = false; for (int i = 0; i < n; i++) { if (vis[i] == 0) { int v = i; int len = 0; while (vis[v] == false) { vis[v] = true; len++; v = nast[v]; } if (len == 1) { // OK } else if (len == 2) { swap_elems(i, nast[i], second); } else { int a = i; int b = nast[nast[i]]; swap_elems(a, b, second); while (true) { a = pop[b]; b = nast[b]; if (a == b) break; swap_elems(a, b, second); } } } } if (first.empty()) { cout << 0 << "\n"; } else if (second.empty()) { cout << 1 << "\n"; cout << first.size() << "\n"; while (!first.empty()) { cout << first.front() << " "; first.pop_front(); } } else { cout << 2 << "\n"; cout << first.size() << "\n"; while (!first.empty()) { cout << first.front() << " "; first.pop_front(); } cout << "\n"; cout << second.size() << "\n"; while (!second.empty()) { cout << second.front() << " "; second.pop_front(); } } } |