#include <bits/stdc++.h>
using namespace std;
inline int in() {
int result = 0;
char ch = getchar_unlocked();
while(true) {
if(ch >= '0' && ch <= '9')
break;
ch = getchar_unlocked();
}
result = ch-'0';
while(true) {
ch = getchar_unlocked();
if (ch < '0' || ch > '9')
break;
result = result*10 + (ch - '0');
}
return result;
}
inline void out(int x) {
if(!x) {
putchar_unlocked('0');
return;
}
if(x<0) {
putchar_unlocked('-')
x=-x;
}
int rev=x, c=0;
while(!(rev%10)) {
++c;
rev/=10;
}
rev=0;
while(x) {
rev=rev*10+x%10;
x/=10;
}
while(rev) {
putchar_unlocked(rev%10+'0');
rev/=10;
}
while(c--)
putchar_unlocked('0');
}
const int mxN=2e5;
int n, m, s, d, a, b, da[mxN], db[mxN], qu[mxN], qh, qt, dp[mxN];
vector<int> adj[mxN];
inline void bfs(int s, int dist[mxN]) {
qh=qt=0;
memset(dist, 0x3F, 4*n);
qu[qt++]=s;
dist[s]=0;
while(qh<qt) {
int u=qu[qh++];
for(int v : adj[u]) {
if(dist[v]>n) {
qu[qt++]=v;
dist[v]=dist[u]+1;
}
}
}
}
int cdp(int u) {
if(!dp[u]) {
dp[u]=da[u];
for(int v : adj[u])
if(da[v]==da[u]-1&&da[v]==db[v])
dp[u]=min(cdp(v), dp[u]);
}
return dp[u];
}
int main() {
n=in(), m=in(), s=in()-1, d=in()-1, a=in(), b=in();
while(m--) {
int u=in()-1, v=in()-1;
adj[u].push_back(v);
adj[v].push_back(u);
}
bfs(a, da);
bfs(b, db);
if(da[s]!=db[s]||da[d]!=db[d])
out(max(min(da[d]-da[s], db[d]-db[s]), -1));
else
out(max(da[d]-da[s]-(cdp(d)<cdp(s)), -1));
}
Compilation message
007.cpp: In function 'void out(int)':
007.cpp:28:3: error: expected ';' before 'x'
x=-x;
^
