#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> II;
const int maxn = 3e5 + 5, logN = 20;
const int MOD = 1e9 + 7;
const ll INF = 1e9;
struct edge{
int u, v, w;
edge(int _u = 0, int _v = 0, int _w = 0) : u(_u), v(_v), w(_w) {}
bool operator < (const edge &op) const{
return w < op.w;
}
}ed[maxn];
int n, m, par[maxn], f[maxn][logN], up[maxn], L[maxn], R[maxn], depth[maxn], val[maxn];
vector<int> g[maxn];
bool isline[maxn];
int get(int u){
if(par[u] != u) par[u] = get(par[u]);
return par[u];
}
void dfs(int u, int p){
up[u] = ((isline[u] == false) ? u : up[p]);
depth[u] = depth[p] + 1;
f[u][0] = p;
for(int i = 1; i < logN; i ++) f[u][i] = f[f[u][i - 1]][i - 1];
for(int v : g[u]){
dfs(v, u);
}
}
int lca(int u, int v){
if(depth[u] < depth[v]) swap(u, v);
for(int i = logN - 1; i >= 0; i --){
if(depth[f[u][i]] >= depth[v]) u = f[u][i];
}
if(u == v) return u;
for(int i = logN - 1; i >= 0; i --){
if(f[u][i] != f[v][i]) u = f[u][i], v = f[v][i];
}
return f[u][0];
}
void init(int N, int M, vector<int> U, vector<int> V, vector<int> W){
n = N, m = M;
for(int i = 1; i <= m; i ++) ed[i] = edge(U[i - 1] + 1, V[i - 1] + 1, W[i - 1]);
sort(ed + 1, ed + m + 1);
for(int i = 1; i <= n; i ++) L[i] = R[i] = i, isline[i] = true;
for(int i = 1; i <= n + m; i ++) par[i] = i;
for(int i = 1; i <= m; i ++){
int u = ed[i].u, v = ed[i].v, w = ed[i].w;
u = get(u), v = get(v);
par[u] = par[v] = i + n;
val[i + n] = w;
isline[i + n] = (isline[u] && isline[v] && (u != v));
bool flag = false;
if(isline[i + n]){
bool flag = false;
for(int x : {L[u], R[u]}){
for(int y : {L[v], R[v]}){
if((x == ed[i].u && y == ed[i].v) || (x == ed[i].v && y = ed[i].u)){
L[i + n] = L[u] ^ R[u] ^ x;
R[i + n] = L[v] ^ R[v] ^ y;
flag = true;
break;
}
}
}
isline[i + n] &= flag;
}
g[i + n].push_back(u);
if(u != v) g[i + n].push_back(v);
}
dfs(n + m, 0);
}
int getMinimumFuelCapacity(int X, int Y){
if(isline[n + m]) return -1;
return val[up[lca(X + 1, Y + 1)]];
}
Compilation message
swap.cpp: In function 'void init(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
swap.cpp:65:87: error: lvalue required as left operand of assignment
65 | if((x == ed[i].u && y == ed[i].v) || (x == ed[i].v && y = ed[i].u)){
| ~~~~~~~~~~~~~^~~~
swap.cpp:60:20: warning: unused variable 'flag' [-Wunused-variable]
60 | bool flag = false;
| ^~~~
