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mirror of https://git.sb/baoshuo/OI-codes.git synced 2024-11-08 14:18:47 +00:00
Baoshuo Ren 2022-08-06 21:18:29 +08:00
parent 3bb90b57d0
commit 21da2a9c7b
Signed by: baoshuo
GPG Key ID: 00CB9680AB29F51A

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AcWing/257/257.cpp Normal file
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#include <iostream>
#include <array>
#include <utility>
#include <vector>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 20005;
int n, m;
std::array<int, N> color;
std::array<std::vector<std::pair<int, int>>, N> g;
bool dfs(int u, int color, int limit) {
::color[u] = color;
for (auto e : g[u]) {
int v = e.first,
w = e.second;
if (w <= limit) continue;
if (::color[v]) {
if (::color[v] == color) return false;
} else if (!dfs(v, 3 - color, limit)) {
return false;
}
}
return true;
}
bool check(int limit) {
std::fill(color.begin(), color.end(), 0);
for (int i = 1; i <= n; i++) {
if (!color[i]) {
if (!dfs(i, 1, limit)) return false;
}
}
return true;
}
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> m;
for (int i = 1, u, v, w; i <= m; i++) {
cin >> u >> v >> w;
g[u].emplace_back(v, w);
g[v].emplace_back(u, w);
}
int l = 0, r = 1e9, ans = 0;
while (l <= r) {
int mid = (l + r) >> 1;
if (check(mid)) {
ans = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
cout << ans << endl;
return 0;
}