Submission #1499183
Source Code Expand
#include <bits/stdc++.h> #define repeat(i,n) for (int i = 0; (i) < (n); ++(i)) #define repeat_from(i,m,n) for (int i = (m); (i) < (n); ++(i)) #define whole(f,x,...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x) using namespace std; template <class T> void setmax(T & a, T const & b) { if (a < b) a = b; } template <class T> void setmin(T & a, T const & b) { if (b < a) a = b; } template <typename X, typename T> auto vectors(X x, T a) { return vector<T>(x, a); } template <typename X, typename Y, typename Z, typename... Zs> auto vectors(X x, Y y, Z z, Zs... zs) { auto cont = vectors(y, z, zs...); return vector<decltype(cont)>(x, cont); } const int inf = 1e9+7; class TreeDistanceConstruction { public: vector<int> construct(vector<int> d); }; vector<int> TreeDistanceConstruction::construct(vector<int> d) { int n = d.size(); vector<int> result; int min_d = *whole(min_element, d); int cnt_min_d = whole(count, d, min_d); if (cnt_min_d == 1 or cnt_min_d == 2) { // construct int l = whole(find, d, min_d) - d.begin(); int r; if (cnt_min_d == 1) { r = l; } else { r = find(d.begin() + l + 1, d.end(), min_d) - d.begin(); result.push_back(l); result.push_back(r); } int m = l; int tick = 0; vector<int> que(n); whole(iota, que, 0); whole(sort, que, [&](int i, int j) { return d[i] < d[j]; }); repeat_from (top, cnt_min_d, n) { int i = que[top]; if (d[m] + 1 < d[i]) { tick = 0; m = l; } if (tick == 0) { result.push_back(l); result.push_back(i); l = i; } else if (tick == 1) { result.push_back(r); result.push_back(i); r = i; } else { result.push_back(m); result.push_back(i); } ++ tick; } } else { // impossible } if (not result.empty()) { // validate vector<vector<int> > dist = vectors(n, n, inf); repeat (i,n) dist[i][i] = 0; repeat (i,n-1) { int u = result[2*i ]; int v = result[2*i+1]; dist[u][v] = 1; dist[v][u] = 1; } repeat (k,n) { // W/F repeat (i,n) { repeat (j,n) { setmin(dist[i][j], dist[i][k] + dist[k][j]); } } } vector<int> eccentricity(n); repeat (i,n) { repeat (j,n) { setmax(eccentricity[i], dist[i][j]); } } repeat (i,n) { if (d[i] != eccentricity[i]) { result.clear(); } } } return result; } int main() { int n; cin >> n; vector<int> a(n); repeat (i,n) cin >> a[i]; cout << (TreeDistanceConstruction().construct(a).empty() ? "Impossible" : "Possible") << endl; return 0; }
Submission Info
Submission Time | |
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Task | C - Tree Restoring |
User | kimiyuki |
Language | C++14 (Clang 3.8.0) |
Score | 0 |
Code Size | 3193 Byte |
Status | CE |
Compile Error
./Main.cpp:1:10: fatal error: 'bits/stdc++.h' file not found #include <bits/stdc++.h> ^ 1 error generated.