#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
int a,b;
int operator()(const int x)const{
return a*x+b;
}
};
bool check(line l1,line l2,line l3){
return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
const int mxn=2e5+5;
vector<tuple<int,int,int>>adj[mxn];
int dp[mxn][2];
int ans=0;
void dfs(int v,int pa){
for(auto [u,d,d2]:adj[v]){
if(u==pa){
//dp[pa][1]+=dp[v][1]+d;
continue;
}
dp[u][0]+=dp[v][0]+d;
dfs(u,v);
dp[v][1]+=d2+dp[u][1];
}
}
int all;
void calc(int v,int pa){
ans=min(ans,all-dp[v][0]-dp[v][1]);
debug(v,dp[v][0],dp[v][1]);
int sum=0;
for(auto [u,d,d2]:adj[v]){
if(u==pa)continue;
debug(dp[u][0],dp[v][1]-d2);
dp[u][0]+=dp[v][1]-d2;
calc(u,v);
dp[u][0]-=dp[v][1]-d2;
}
}
signed main(){
setio();
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int n;
cin>>n;
ans=1e18;
for(int i=1;i<n;i++){
int a,b,c,d;
cin>>a>>b>>c>>d;
adj[a].pb({b,c,d});
adj[b].pb({a,d,c});
all+=c+d;
}
dfs(1,1);
debug(all);
for(int i=1;i<=n;i++){
debug(dp[i][0],dp[i][1]);
}
calc(1,1);
cout<<ans<<'\n';
}
/*
input:
*/
Compilation message
designated_cities.cpp: In function 'void dfs(long long int, long long int)':
designated_cities.cpp:59:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
59 | for(auto [u,d,d2]:adj[v]){
| ^
designated_cities.cpp: In function 'void calc(long long int, long long int)':
designated_cities.cpp:74:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
74 | for(auto [u,d,d2]:adj[v]){
| ^
designated_cities.cpp:73:9: warning: unused variable 'sum' [-Wunused-variable]
73 | int sum=0;
| ^~~
designated_cities.cpp: In function 'void setIO(std::string)':
designated_cities.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
42 | freopen((s + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
designated_cities.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
43 | freopen((s + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
6232 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
5980 KB |
Output is correct |
| 2 |
Incorrect |
128 ms |
27656 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
5976 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
6232 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
5980 KB |
Output is correct |
| 2 |
Incorrect |
128 ms |
27656 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
6232 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
