#include "supertrees.h" #include <vector> #include<bits/stdc++.h> using namespace std; struct DSU { /* data */ int n; vector<int> par, sz; void init(int _n) { n = _n; par.resize(n + 1, -1); sz.resize(n + 1, 0); } int finds(int a) { if(par[a] == -1) return a; return par[a] = finds(par[a]); } void unites(int a, int b) { int x = par[a]; int y = par[b]; if(x != y) { if(sz[x] < sz[y]) swap(x, y); par[y] = x; sz[x] += sz[y]; } } }; int construct(std::vector<std::vector<int>> p) { int n = p.size(); DSU d; d.init(n); for(int i=0;i<n-1;i++) { for(int j=i+1;j<n;j++) { if(p[i][j]) d.unites(i, j); } } vector<vector<int>> ans(n, vector<int>(n, 0)); map<int, vector<int>> mp; for(int i=0;i<n;i++) { mp[d.finds(i)].push_back(i); for(int j=0;j<n;j++) { if(i == j) continue; if(p[i][j] == 0) if(d.finds(i) == d.finds(j)) return 0; } } for(auto a:mp) { for(int i=0;i<a.second.size() - 1;i++) ans[a.second[i]][a.second[i + 1]] = ans[a.second[i + 1]][a.second[i]] = 1; } build(ans); return 1; }

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:65:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |   for(int i=0;i<a.second.size() - 1;i++)
      |               ~^~~~~~~~~~~~~~~~~~~~