#include <bits/stdc++.h>
#include "simurgh.h"
using namespace std;
vector< int > U;
int getParents(int a){
if(U[a] == a) return a;
else return U[a] = getParents(U[a]);
}
void Union(int a, int b){
U[getParents(a)] = getParents(b);
}
int makeBetter(vector< tuple<int, int, int> > &golden, vector< tuple<int, int, int> > &rem, int start, int n){
for(int i = 0; i < n-1; i++){
for(int j = 0; j < n;j++){
U[j] = j;
}
vector< tuple<int, int, int> > tempo;
vector< int > ans;
for(int j = 0; j < n-1; j++){
if(j == i) continue;
assert(getParents(get<0>(golden[j])) != getParents(get<1>(golden[j])));
Union(get<0>(golden[j]), get<1>(golden[j]));
tempo.push_back(golden[j]);
ans.push_back(get<2>(golden[i]));
}
for(int j = 0; j < (int)rem.size(); j++){
if(getParents(get<0>(rem[j])) == getParents(get<1>(rem[j]))) continue;
ans.push_back(get<2>(golden[i]));
int x = count_common_roads(ans);
if(x > start){
golden = tempo;
golden.push_back(rem[j]);
swap(rem[j], rem.back());
rem.pop_back();
rem.push_back(golden[i]);
return x;
}
ans.pop_back();
}
}
return start;
}
vector<int> find_roads(int n, vector<int> u, vector<int> v) {
U.resize(n);
for(int i = 0; i < n; i++){
U[i] = i;
}
vector< tuple<int, int, int> > golden;
vector< tuple<int, int, int> > rem;
for(int i = 0; i < (int)u.size(); i++){
if(getParents(u[i]) == getParents(v[i])){
rem.push_back(make_tuple(u[i], v[i], i));
continue;
}
golden.push_back(make_tuple(u[i], v[i], i));
Union(u[i], v[i]);
}
int start = count_common_roads(golden);
while(start < n-1){
start = makeBetter(golden, rem, start,n);
}
vector< int > ans;
for(int i = 0; i < n-1; i++){
ans.push_back(get<2>(golden[i]));
}
return ans;
}
Compilation message
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:79:39: error: invalid initialization of reference of type 'const std::vector<int>&' from expression of type 'std::vector<std::tuple<int, int, int> >'
int start = count_common_roads(golden);
^
In file included from simurgh.cpp:2:0:
simurgh.h:4:5: note: in passing argument 1 of 'int count_common_roads(const std::vector<int>&)'
int count_common_roads(const std::vector<int>& r);
^~~~~~~~~~~~~~~~~~
