#include <bits/stdc++.h>
using namespace std;
#ifdef MIKU
string dbmc = "\033[1;38;2;57;197;187m", dbrs = "\033[0m";
#define debug(x...) cout << dbmc << "[" << #x << "]: ", dout(x)
void dout() { cout << dbrs << endl; }
template <typename T, typename ...U>
void dout(T t, U ...u) { cout << t << (sizeof...(u) ? ", " : ""); dout(u...); }
#else
#define debug(...) 39
#endif
#define fs first
#define sc second
#define mp make_pair
#define FOR(i, j, k) for (int i = j, Z = k; i < Z; i++)
using ll = long long;
typedef pair<int, int> pii;
namespace {
const int MXN = 100005;
int n, m, len;
vector<pii> edge[MXN];
vector<int> rt;
bitset<MXN> b;
vector<int> now, A;
int ans;
struct P {
pii a[2];
void init() {
a[0] = mp(0, 0);
a[1] = mp(0, 0);
}
void add(pii x) {
if (x >= a[0]) {
a[1] = a[0];
a[0] = x;
} else a[1] = max(a[1], x);
}
int get(int x = 0) {
return (x == a[0].sc ? a[1].fs : a[0].fs);
}
} dp[MXN];
void DFS1(int id, int par) {
b[id] = true;
now.push_back(id);
dp[id].init();
for (auto &[w, i] : edge[id]) {
if (i == par) continue;
DFS1(i, id);
dp[id].add(mp(dp[i].get() + w, i));
}
}
void DFS2(int id, int par, int ww) {
if (par) dp[id].add(mp(dp[par].get(id) + ww, par));
for (auto &[w, i] : edge[id]) {
if (i == par) continue;
DFS2(i, id, w);
}
}
void DP(int rt) {
debug(rt);
DFS1(rt, 0);
DFS2(rt, 0, 0);
}
pii calc() {
int big = 0, sml = INT_MAX;
for (auto &i : now) {
big = max(big, dp[i].get());
sml = min(sml, dp[i].get());
}
return mp(big, sml);
}
int solve() {
FOR(i, 1, n + 1) {
if (b[i]) continue;
DP(i);
auto [big, a] = calc();
ans = max(ans, big);
A.push_back(a);
now.clear();
}
debug(ans);
// assert(A.size() == 2);
// ans = max(ans, A[0] + A[1] + len);
// cout << "A: ";
// for (auto &i : A) cout << i << ' ';
// cout << '\n';
if (A.size() == 1) return ans;
if (A.size() == 2) return max(ans, A[0] + A[1] + len);
sort(A.begin(), A.end(), greater<int>());
return max(ans, max(A[0] + A[1] + len, A[1] + A[2] + 2 * len));
}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
::n = N;
::m = M;
::len = L;
FOR(i, 0, M) {
edge[++A[i]].push_back(mp(T[i], ++B[i]));
edge[B[i]].push_back(mp(T[i], A[i]));
}
return solve();
}
#ifdef MIKU
int a[MXN], bb[MXN], t[MXN];
void miku() {
int n, m, l;
cin >> n >> m >> l;
FOR(i, 0, m) {
cin >> a[i] >> bb[i] >> t[i];
}
cout << travelTime(n, m, l, a, bb, t) << '\n';
}
int32_t main() {
cin.tie(0) -> sync_with_stdio(false);
cin.exceptions(cin.failbit);
miku();
return 0;
}
#endif
Compilation message
dreaming.cpp: In function 'void {anonymous}::DP(int)':
dreaming.cpp:11:20: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 39
| ^~
dreaming.cpp:67:9: note: in expansion of macro 'debug'
67 | debug(rt);
| ^~~~~
dreaming.cpp: In function 'int {anonymous}::solve()':
dreaming.cpp:11:20: warning: statement has no effect [-Wunused-value]
11 | #define debug(...) 39
| ^~
dreaming.cpp:90:9: note: in expansion of macro 'debug'
90 | debug(ans);
| ^~~~~
/usr/bin/ld: /tmp/ccIPT82T.o: in function `main':
grader.c:(.text.startup+0xd1): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
