#include "supertrees.h"
#include<bits/stdc++.h>
using namespace std;
void markall(int i ,int j ,vector<int>&f,vector<int>&b,vector<vector<int>>&p,vector<vector<int>>answer){
int k = b[i];
while(k!=-1){
int u = j;
while(u!=-1){
p[k][u]--;
p[u][k]--;
u=f[u];}
k=b[k];
}
}
bool check(vector<int>f,vector<int>b,int i ,int j,vector<vector<int>>p){
int k = b[i];
while(k!=-1){
int u = j;
while(u!=-1){
if (p[k][u]<=0)return false;
u=f[u];}
k=b[k];
}
return true;
}
int construct(vector<std::vector<int>> p) {
int n = p.size();
vector<vector<int>>answer(n,vector<int>(n,0));
for (int i =0;i<n;++i){
p[i][i]=0;
}
for (int i =0;i<n;++i){
for (int j =0;j<i;++j){
if (p[i][j]>=3)return 0;
}
}
vector<int>f(n,-1),b(n,-1);
for (int i =0;i<n;++i){
for (int j =0;j<n;++j){
if (p[i][j]>0){
if (f[i]==-1&&b[j]==-1&&check(f,b,i,j,p)){
f[i]=j;
b[j]=i;
answer[i][j]++;
answer[j][i]++;}
markall(i,j,f,b,p,answer);
}
}}
for (int i =0;i<n;++i){
for (int j =0;j<n;++j){
if (p[i][j]>0)return 0;
}
}
build(answer);
return 1;
}
